Location: Third Floor, Wing B
Hours: Monday through Friday, 7:30 a.m. to 4:30 p.m.
About us: We offer drug and alcohol evaluation, education, and treatment. Outpatient treatment is available.
Location: Third Floor, Wing D
About us: We provide evaluation and diagnostic assessment of allergy related diseases for active duty and beneficiaries assigned to Joint Base San Antonio-Lackland. Patients who desire to be evaluated by the allergy clinic must have a consult placed by their primary care manager.
Location: Second Floor, Wing A
Hours: Monday, Wednesday, and Friday, 6:30 a.m. to 12 p.m.
Location: Second Floor, Wing D
Hours: 7:30 a.m. to 4:30 p.m.
About us: We provide comprehensive hearing and balance assessment services to active duty personnel and eligible family members. A referral is needed to receive hearing or balance services.
Location: Reid Clinic
About us: We provide cardiac consultations for active duty members assigned to Joint Base San Antonio-Lackland. A referral is needed in order to receive cardiology services, to include procedures and consultation.
Location: First Floor, Wing C
Hours: 7 a.m. to 4 p.m.
About us: We see patients by referral only. Follow-up appointments are scheduled by the chiropractic staff.
Hours: 7 a.m. to 4 p.m.
About us: We diagnoses and treat diseases of the skin, hair, nails, and mucous membranes. Appointments in are by consultation only through your primary care manager.
About us: The Diabetes Center of Excellence is a premier Air Force Medical Service specialty clinic dedicated to providing standardized diabetes care to beneficiaries across the military health care system. The clinic includes three equally important sections: clinical division, outreach division, and research division. The clinical component provides diabetes management, diabetes education, and diabetes prevention programs.
About us: We treat a variety of issues, including sinuses, tonsils, ears and hearing, facial aesthetics, facial nerve, salivary glands, nose, upper aero digestive tract, thyroid, parathyroid, voice and speech problems, tracheotomies, and many other issues. Areas excluded from clinic management include the brain, the eye, the carotid arteries, and the spinal cord and associated vertebral column.
Location: Room 1T07 or 1T09, First Floor, Wing C
Hours: 8 a.m. to 4 p.m.
About us: The Air Force Exceptional Family Member Program is designed to provide support to military family members with special needs. Learn more about about the Exceptional Family Member Program.
Location: First Floor
Hours: Always open
About us: We are pleased to once again provide emergency care on Joint Base San Antonio-Lackland. We diagnose and treat a variety of emergency and non-emergency illnesses and injuries in both children and adults. The Family Emergency Center provides open access care for all eligible Department of Defense beneficiaries. Whether you're suffering from head, chest, or abdominal pain; fractured, sprained, or broken bones; shortness of breath; vomiting; dehydration; or even seemingly mild symptoms like a fever or sore throat, you can trust that our team of experienced medical professionals will treat you as if you're the most important person in our facility, and provide you with friendly, immediate, patient-centered care.
Location: First Floor, A-Wing
Hours: 6:30 a.m. to 4 p.m.
Telephone: 210-292-4980 or 210-292-0020
About us: The Gastroenterology Clinic enhances Air Force readiness by promoting healthy families through early digestive disease identification, monitoring, and treatment. Adult patients are accepted based on care requirements through physician referral. The clinic provides a wide variety of endoscopy services including: upper endoscopy, colonoscopy, sigmoidoscopy, and enteroscopy. These procedures serve as both diagnostic and treatment platforms. During the course of these procedures physicians may perform tissue biopsies, polyp excision, gastrointestinal hemorrhage control, diagnostic photography, obstruction removal, stricture dilation, internal hemorrhoid ligation.
Location: Second Floor, Wing C
Telephone: 210-292-7293 or 210-292-7294
About us: Examples of specialties are colo-rectal surgery, minor-minimally invasive surgery and wound, or ostomy, services. We address a wide range of problems within the human body. Gallbladder, intestinal, and hernia related issues are commonly dealt with by general surgeons, but general surgeons can manage surgical problems in body systems including the thyroid, parathyroid, lungs, stomach, liver, intestines, colon, and many other body systems. Generally excluded from a general surgeons practice include the skeletal system, neurological system, and the genitourinary system.
About us: The Immunizations Clinic serves patients of all ages. Walk-in and same-day immunizations are administered during normal duty hours. Beneficiaries should bring in all immunization documentation when visiting for the first time or if immunizations were received from an outside facility. The Immunizations Clinic is a walk-in clinic. Please note that patients may experience increased wait times depending on patient volume.
Location: First Floor, Wing B
About us: For related services,please bring all documentation pertaining to clearance to the clinic for review prior to your appointment. For permanent change of station, security, deployment, re-training, cross training, contact the Base Operational Medicine Clinic to initiate process. Referrals are required for services.
About us: We use evidence-based Medical Nutrition Therapy to provide cutting-edge nutrition services to our active duty, dependent and retiree community. Classes and individual appointments are offered.
About us: Ophthalmology is a branch of medicine specializing in the anatomy, function, and diseases of the eye. A team staff ophthalmologists and residents are available to provide complete vision care. Wilford Hall Ophthalmology Department accommodates patient care in general ophthalmology and six sub-specialties.
Hours: 6:30 a.m. to 4:30 p.m.
About us: We see patients by referral only for musculoskeletal and neuromusculoskeletal disorders. Please arrive 15 minutes early; keep in mind if you need X-rays while at the clinic, or if your physician does not have your outpatient record, you may incur extra waiting time. Bring these items with you, if possible: current X-rays, MRIs, or CT scans pertaining to your symptoms if you're referred from outside of Wilford Hall Ambulatory Surgical Center; appropriate clothing for an exam.
Location: First Floor, Wing D
About us: The Pediatric Clinic provides services by appointment only to enrolled patients, newborn to 23 years.
Hours: 6:30 a.m. to 4:30 p.m.
Computed Tomography (CT)
Hours: 7 a.m. to 5 p.m.
Diagnostic Imaging (X-Ray)
Magnetic Resonance Imaging (MRI)
About us: We do not have an open magnet for those patients suffering from claustrophobia. If you feel you are claustrophobic, please alert your provider for further consult.
About us: We perform FDA-approved PRK, LASEK, and LASIK treatments; including custom wave-front guided treatments. Refractive surgery is only available to active-duty military members.
Outpatient Physical Therapy
Location: Third Floor, Wing C
About us: Outpatient physical therapy is a rehabilitation setting in which we use therapeutic procedures to help patients regain normal physical mobility and activities of daily living. The PT clinic uses individualized programs based on an initial evaluation to promote the ability to move, reduce pain, restore function, prevent disability or achieve other specific goals. Our clinic utilizes a variety of techniques to include therapeutic exercise, manual therapy, modalities and pool therapy to achieve those goals.
About us: The Occupational Therapy Clinic offers a wide range of therapeutic and rehabilitation services for upper extremity pathologies and physical dysfunction. Based on a referral from a patient's provider, OT uses state-of-the-art tools, equipment and hands-on expertise to deliver top-notch care to beneficiaries. OT utilizes leading edge technology and treatment modalities to treat a myriad of upper extremity cumulative and acute trauma. The goal of OT is to return a patient to the maximal functional level of performance of activities of daily living prior to onset of injury or illness. Our clinic has the resources needed to fabricate custom hand, wrist and elbow splints as well as providing patient education on work task modification, energy conservation, work simplification, prevention and rehabilitation to promote an overall healthier lifestyle.
Location: Third Floor, Wing C
About us: The Orthotic Laboratory also known as the brace shop is located in the basement of Wilford Hall, near the clinic entrance just around the corner from the Orthopedic Clinic. We provide orthotic services for pediatric, adolescent, adult, and geriatric patients. Braces such as wrist, neck, back, knee, ankle braces and arch supports are available. We accept prescriptions from both military and civilian providers. Patients are required to bring their prescription and their military ID card to obtain treatment. Care is provided on a walk-in basis with minimal wait times. Some specialty items such as custom-made arch supports require a prescription from either a podiatrist or orthopedic surgeon.
About us: Urology is a diverse specialty that encompasses the medical and surgical treatment of many diseases affecting the genitourinary systems. The spectrum of pathologies covered and treatments offered is immense considering the small volume of the body that we serve. We provide diagnostic services to adult patients with genitourinary disorders. Minor procedures such as cystoscopy, vasectomy, prostate biopsy are available. Pediatric and Surgical Urology services are provided at our sister clinic, located at the San Antonio Military Medical Center on Joint Base San Antonio-Fort Sam Houston.
Pregnancy & Warfarin
Warfarin is a safe drug when administered and monitored properly. Indeed, oral anticoagulation is a vital treatment for certain conditions, such as those listed on the Indications page of his symposium. However, one of the drawbacks for Warfarin is the potential for birth defects and/or hemorrhage in the offspring of mothers taking the drug.
There is apparently a link between some birth defects and Warfarin taken by the mother during early pregnancy. The actual degree (or percentage) of risk to the unborn child is not known. In most circumstances, Warfarin should be avoided in women of childbearing age unless there is no other option. If possible, another anticoagulant regimen should be used.
However, there are situations in women of child-bearing age where Warfarin is still the mainstay of therapy, such as recurrent pulmonary emboli. If a young woman needs to start Warfarin during the child-bearing years, it is very important to educate the patient on the potential harm to the unborn child and establish an effective birth control plan.
Before starting therapy, female patients should be asked about their intent to bear children in the future, their birth control methods at present, and their religious beliefs. For the woman who is not planning or desiring further children, sterilization by tubal ligation or hysterectomy would be the most reliable preventative step.
In younger women anticipating a new or enlarging family, Warfarin should not be prescribed if any other possible choice can be used. For some patients, this might mean daily shots with heparin, another anticoagulant medication which cannot be given by mouth.
If Warfarin is still required for clinical reasons, then birth control intervention must be prescribed as well. A longer acting form of birth control should be used (consult your GYN provider), since daily birth control pills could be accidentally or purposefully discontinued, risking an unwanted or unexpected pregnancy while taking Warfarin.
Educational services like Planned Parenthood can assist in selecting birth control methods that are acceptable to the patient and their lifestyle and/or values. Prevention is far better than dealing with the consequences after a pregnancy has occurred.
Occasionally a woman is diagnosed with heart or vascular problems during pregnancy. The most common form of heart problem discovered during pregnancy is mitral stenosis (from prior rheumatic fever). Some of these mothers will not survive delivery if the heart disease is left untreated. Intervention may require heart valve surgery even during the later half of the pregnancy.
Fortunately, the fetus tolerates heart surgery remarkably well and spontaneous loss of the pregnancy is rare. If possible, a tissue heart valve design should be used in this setting. Nearly all of these valves can be used without the need for Warfarin. However, if anticoagulation is required during pregnancy for any reason, it is best to administer heparin instead of Warfarin. Heparin cannot be given by mouth, and must be administered by shots under the skin three times per day, or by continuous intravenous infusion. Some pregnant mothers with heart problems or clotting problems will be placed on heparin shots for many months before the birth of their child. Fortunately, there is no known association between heparin and birth defects.
Dietary Considerations in Warfarin Patients
Warfarin acts by impairing the utilization of Vitamin K. The liver requires Vitamin K for the manufacturing of certain key proteins in the native clotting mechanism. When Vitamin K is not made available, these clotting factors are not manufactured, and blood clotting is impaired. At the same time, oral intake of Vitamin K will thus counteract the medicinal purpose of Warfarin, essentially acting as the antidote for Warfarin.
Sudden intake of large amounts of Vitamin K can diminish the effect of Warfarin, permitting the blood to clot. Some physicians place Warfarin patients on strict Low-Vitamin-K diets. Foods that are high in Vitamin K are discouraged. However, dietary restrictions rarely succeed over a long period of time.
Most patients return to eating their favorite foods, gradually at first. Thus the more prudent approach for Warfarin maintenance is to adjust the medication, not the diet. That is one of the very reasons for repeating the Pro-Time until a steady dose is found that provides the right anticoagulation regardless of the dietary intake of the patient. For your information, the following lists presents foods known to be high in Vitamin K.
If your regular diet already contains these food items, Don't Change Your Eating Habits. Consistency in your daily eating pattern is the key. If you move to a new climate, or change your eating habits for any other reason, a new series of Pro-Times will be needed to make certain that your Warfarin requirement has not changed. However, even if it has changed, the best option is to change the dose which you take.
The information provided in this educational forum is solely for your information, and is not intended to replace actual recommendations or advice given by your treating physician.
Your Diet & Vitamin K
Warfarin works to keep your blood from clotting by decreasing the availability of Vitamin K. Vitamin K helps your blood to clot. These are opposing actions. Excessive Vitamin K intake can interfere with the Warfarin and allow your blood to remain susceptible to clots. Likewise, if you eat too little Vitamin K, the excess medication may cause your blood to become too thin. Your medication will be adjusted to the amount of Vitamin K typically in your diet. If you suddenly increase or decrease the amount of Vitamin K in your diet, your medication will not work properly.
A healthy, low fat diet following the Food Guide Pyramid is the best diet to follow. It is important for you to keep the Vitamin K content of your diet consistent. The amount of Vitamin K you eat affects the amount of Warfarin you require. Be sure to tell your healthcare provider if you change your diet. The medication will need to be adjusted to the amount of Vitamin K in your diet.
Some foods that are high in Vitamin K (i.e., leafy, green vegetables, broccoli, and cauliflower) can contribute to a healthy diet. Your efforts should be focused on keeping your intake of Vitamin K consistent from day to day. The first step is to evaluate your typical intake of Vitamin K foods by reviewing the food list in this packet.
Although there is little information about the effects of cooking, freezing, or drying on the Vitamin K content of foods, it appears that the Vitamin K content of cooked, frozen, or dried foods is about the same as fresh foods.
Evaluate your typical Vitamin K intake by reviewing the food list provided. The list contains foods that are known to be high in Vitamin K, as well as a few others that are not very high, but are often asked about by Warfarin patients. If you do not see a particular food on the list, it most likely contains very little Vitamin K, however, be sure to ask you dietitian about the food if you are concerned.
First, review the list to find foods that you are presently eating. Each list is identical. The first organizes foods from the highest Vitamin K content to lowest, while the second is in alphabetical order. Observe the amount of Vitamin K contained in the foods you eat. If you typically eat a larger portion than what is listed, be sure to increase the Vitamin K value proportionally. (i.e., there is 40ug of Vitamin K in ½ cup of lettuce, but you eat 2 cups worth in your salad, so you would actually have 160ug of Vitamin K in total). Add up the total amount of vitamin K that you typically consume in a day. Whatever it may be, 100, 200, 300, 400ug, etc., your job is to keep this daily intake as consistent as possible. By selecting combinations of foods, and/or adjusting portion sizes you should be able to consume about the same amount of Vitamin K each day.
If you should ever decide to dramatically change your typical daily intake of Vitamin K, be sure to inform your Doctor or pharmacist BEFORE making the change. They will most likely need to adjust your Warfarin dosage.
CAUTION - The following should be taken only with your physician's approval, because they also thin your blood, thus increasing the effect of your medication: alcohol, garlic pills, fish oil capsules, Vitamin E. Vitamin K tablets can also interfere with your Warfarin medication. Be sure to get your physician's approval, if you take Vitamin K tablets or a multi-vitamin pill with Vitamin K included. If you should have any additional questions or concerns regarding your daily intake of Vitamin K, please contact a dietitian at phone number (210) 292-7587 or 7472.
Highest to Lowest Vitamin K Content (Listed by food item, portion size and Vitamin K content)
Vitamin K Content by Food Item (Listed by food item, portion size and Vitamin K content)
**Current analytical findings indicate that the brew from green tea leaves has negligible Vitamin K content.
Conditions Treated with Warfarin
Medical Conditions Commonly Treated with Warfarin Anticoagulation
Blood is meant to flow continuously, bringing vital nutrients and oxygen to every cell of the body. Blood should clot only when there is some injury to the blood vessel wall. This is a natural mechanism which prevents potentially fatal bleeding. If blood did not clot when a blood vessel was injured, even minor injuries could cause a person to lose a large amount of blood. Thus nature's defense is the natural clotting action of the blood. As anyone can observe from their own injuries, blood will clot within minutes if the proper conditions are present. In some disease states, clotting occurs when it shouldn't.
Blood clots which form in an abnormal time or location can be dangerous. These clots can break loose from their attachment and migrate into other body organs, causing damage. Large clots can obstruct blood flow.
To treat patients with clotting disorders, anti-clotting (or more appropriately "anticoagulant") medications are prescribed. Many of the indications for prescribing Warfarin are common health problems. A discussion of the most common reasons for prescribing Warfarin is presented below. However, not every patient with the medical conditions listed below will need (or can tolerate) Warfarin. If you have questions about your Warfarin prescription, or the reasons for administering the medication, consult your physician directly.
Conditions Commonly Treated with Warfarin Anticoagulation
Warfarin Interactions with Other Drugs
Drugs Which Interfere with Coumadin® Regulation Increased Warfarin Effect
Decreased Warfarin Effect Highly Probable
No Warfarin Effect Highly Probable
Mechanisms of Warfarin Actions
Warfarin is an anticoagulant drug. It is only available by prescription, and should only be taken under the supervision of a physician familiar with its indications and actions. Warfarin is based on a chemical known as warfarin sodium. Warfarin causes its anti-clotting effect by impairing the production of certain blood clotting proteins by the liver.
Administration of warfarin sodium blocks the action of Vitamin K within the liver. The drug effectively competes for the same absorption sites within the liver needed for Vitamin K uptake. Thus, the levels of Vitamin K within the liver decrease. Reduced amounts of clotting factors VII, IX, X, and II are produced, and the clotting action of the blood is progressively impaired. All of the actions of Warfarin are due to the drug's inhibition of Vitamin K. Thus, ingestion or administration of Vitamin K can reverse the effects of Warfarin. In fact, clinical overdosage with Warfarin is corrected with Vitamin K.
Dietary intake of Vitamin K does affect the metabolism of Warfarin. This is one of the reasons that each patient seems to require a different dose of the drug to reach the target anticoagulation effect. Each person has different dietary intake of Vitamin K, and also different liver function, different excretion of the drug, etc. Thus it is important for the physician to monitor Warfarin effect on the patients clotting mechanism. Without a monitor, patients would frequently be overdosed or underdoses, with potentially hazardous consequences.
Monitoring of the Warfarin effect is performed with a blood test. This test is known as the INR or International Normalization Ratio. It is important that you review the INR information in The Anticoagulation Clinic and become familiar with the routine used to monitor this drugs effect.
Don't Mix Other Medications with Warfarin
The chief precaution with this drug revolves around interactions with other drugs. Some medications magnify the Warfarin effect, and some act as a relative antidote. Many common over-the-counter medications or remedies interfere with Warfarin regulation. Be advised that starting or stopping any medication could potentially affect your Warfarin control.
It is important to recheck your I.N.R. whenever starting or stopping any other medication. Aspirin is the most common drug which affects Warfarin regulation. Alcohol, antacids, antihistamines, antibiotics, and many other common medications also affect Warfarin. A list of medications which are known to interfere with Warfarin is included in this web site.
Follow a Schedule
Take your pill at the same time every day. It is easier to adjust your dose if you take your medicine in the evening. Although Warfarin can be taken any time in the day, it is prudent to take your dose at the same time each evening. If the doctor calls to adjust your dose, it is not much help if you have already taken your pills for the day. Thus the evening dosage schedule allows for easier adjustment. Many patients use a metered pillbox (one slot for each day of the week) and place it next to their toothbrush, for a convenient reminder.
Check Your Pills
It is possible for Warfarin pills to become mixed up. Even pharmacists have occasionally made errors, giving out the wrong tablet strength. Some patients who have had more than one strength of tablet in the household have mixed them up, with a resulting change in therapeutic dose. Keep close track of the color and insignia (indicating milligram strength) on each tablet, and at the time each prescription is filled.
If you are planning to travel outside of the country, refill your prescription. Make sure you have enough tablets for the entire trip, plus extras. Obtain your Pro-Time / I.N.R. before leaving to make sure that your dosage is proper. If you will be out of the area for an extended period of time, ensure that you obtain a "Travel Memorandum" from your provider. A Travel Memorandum allows you to travel and have your blood tested at other facilities that will fax the results back to your physician for them to properly dose and call you with any changes.
Let your family know you are taking anticoagulants. Make sure all your treating physicians know, especially new consultants who you have never seen before. Wear a Medic-Alert band or I.D. bracelet which informs others that you are taking Warfarin. Make sure your dentist is aware as well.
First, let your dentist know that you are taking Warfarin. Have regular check-ups to prevent and treat gum disease that might predispose you to bleeding during brushing or flossing.
Avoid traumatic sports, if possible. Wear protective gear for activities like bicycle or horseback riding. Use a soft toothbrush to prevent gum injury. Use an electric razor rather than a straight or blade razor. Wear gloves while gardening.
Dosing of Warfarin is individualized to each patient. There are different ranges of target values in different situations. It is important to know what target range your physician is using to treat your condition. Continue to have your blood draws as directed by your physician and / or nurse. After each blood draw, keep in touch with your physician's clinic to find out the results and what new dosage may be needed.
Warfarin is contraindicated in pregnancy. If pregnancy is a consideration, please consult your physician as soon as possible, preferably before conception.
What to Look For
The following symptoms could be a sign of excessive Warfarin dosage. If any of these symptoms occur, consult your clinic or physician.
Warfarin (Coumadin®) Tablets - Color & Numerical Value (i.e., Label)
Each tablet is imprinted with a bold-faced numeral, indicating the milligrams of warfarin base in each tablet. There is a dividing line (or "score") across the middle of the front face of each pill. This permits the patient to easily cut the pill into two equal halves with a dull kitchen knife. Notice the similar colors between the 1 (one) milligram (pink) and the 5 (five) milligram (orange) tablet.
You cannot identify the different pills by color alone. Whenever you receive your prescription from the pharmacist, look at the identifying marks on the tablets and confirm the actual dosage with what your doctor prescribed. If the pills do not match, don't ingest any of them. Return them to the pharmacy right away and fill the proper dosage. Ingestion of pills that are too strong can result in serious, potentially harmful, bleeding complications.
Most patients are advised to take their Warfarin pills in the evening time. The action of Warfarin does not depend on the time of day. However, evening dosing of this drug makes it easier to adjust the amount after obtaining the results of the morning blood test. If the Pro-Time or INR indicate that an adjustment is needed, it is best if you have not already taken the dose for that day. For example, if you have your Pro-Time drawn in the morning, but also take your pill in the morning, your doctor would have more difficulty reducing your dosage if you have already taken the medication.
So, evening dosing is preferred in order to make dosing changes quicker and easier. Most patients purchase a 7-day (Monday through Sunday) pillbox. Each Monday, all seven days’ worth of Warfarin is placed into the slots. The pillbox should stay in the bathroom near your toothbrush. The easier way to take Warfarin is at the same time that you brush your teeth at night.
If you have small children in the household, the pillbox must be secured against accidental ingestion by a child. Should this occur, contact the nearest emergency room or poison control center right away. If recognized quickly, the effect of Warfarin can be reversed by administration of Vitamin K. Treatment for Warfarin ingestion would require hospitalization.
Using Warfarin Safely
It is important that you maintain the dosage prescribed for your Warfarin therapy. When you take your Warfarin, check to make sure you are taking the right tablets in terms of:
You must take your Warfarin tablets on an unchanging schedule. You should take them:
If you forget to take a tablet, let your physician know. DO NOT take another tablet to "catch up." Your prescription for Warfarin should be refilled only as directed by your physician. Other medications may affect the action of Warfarin.
You may wish to carry a card that identifies you as a patient on Warfarin.
Women: Warfarin should not be taken while you are PREGNANT. Inform your physician immediately if you are pregnant or if you are planning to become pregnant.
Because may factors can affect the action of Warfarin, it is important that you maintain a consistent lifestyle in terms of:
Avoid excessive use of alcohol. If you wish to change the amount of alcohol you normally drink, tell your physician.
Please check with your physician before starting on any extended trip as this may influence your medication availability, scheduled Protime/I.N.R. test, and eating habits.
Because Warfarin therapy affects the clotting factors in our blood, it is important that you call your physician if any of the following occurs:
An Important Reminder
Please report all Protime/I.N.R. tests at scheduled times. This blood test is important. We will use this test to monitor the therapeutic effect of Warfarin in your blood and make adjustments to your dosage as needed.
If you have any questions about your Warfarin therapy, please ask your physician or clinic personnel.
Hours: Monday through Wednesday, and Friday, 7:30 a.m. to 4:30 p.m.
About us: The Women’s' Health Clinic is a self-referral clinic that provides routine gynecological care to active duty, retirees and their dependents. The clinic ensures optimal care for the patients with gynecological, women's health care issues /illnesses from adolescence through the reproductive years and beyond. Women's health practitioners and a certified nurse midwife provide routine gynecological care including annual well women exams, contraceptive counseling, and evaluation and treatment of minor gynecological problems.