Dear Doctor: I’m confused about fever. What is considered a fever? And if fever is the result of a person’s body fighting a disease, why is it bad for us? It seems to make no sense to treat a person by lowering their fever.

Dear Reader: You’ve asked a fascinating question that, believe it or not, has been a subject of debate for thousands of years.

As you point out, a fever isn’t a disease. Rather, it’s most often a sign that the body is rallying to fend off an infection or illness. What people haven’t been able to agree on is whether or not the fever is beneficial because it fights the invader, or detrimental because of its damaging toll on our bodies.

One line of thinking goes that if an elevated core temperature is helpful at fighting off an illness, we shouldn’t interfere. That’s an idea that dates all the way back to Hippocrates. In fact, the practice of pyrotherapy -- medically inducing a fever -- was used as recently as the late 19th and early 20th century to manage certain types of bacterial infections. Pyrotherapy was largely abandoned once the discovery of penicillin ushered in the era of antibiotics.

The opposing argument is that the metabolic costs of having a fever outweigh the potential benefits. For example, even a moderate fever may pose a danger to people with heart or lung conditions, because it causes heart and respiratory rates to increase. Fever can also adversely affect the mental state of someone with dementia. That means in order to avoid potential complications, fever should be treated.

Small studies have yielded evidence that supports each side of the fever argument. The fact is that centuries later, we still don’t have a definitive answer.

What we do know is that fever is defined as a body temperature of 100.4 degrees Fahrenheit (that’s 38 degrees Celsius) and up. The most common causes of fever are upper and lower respiratory tract infections, gastrointestinal infections and urinary tract infections. Heatstroke, sunstroke, certain cancers, reactions to drugs, allergic reactions and autoimmune disorders can also cause fever.

Symptoms that accompany a fever typically include headache, muscle aches, sweating, chills and shivering, loss of appetite, weakness and generally feeling crummy. Most adults can tolerate temporary fevers up to 104 degrees F. However, this type of fever may signal additional underlying problems. We recommend checking with your doctor if your fever reaches 103 degrees F or more.

To reduce a fever, adults and children over the age of 6 months can use over-the-counter medicines such as ibuprofen or acetaminophen. Although adults can treat a fever with aspirin, it should never be given to children; the use of aspirin in children has been linked to Reyes syndrome, which is a rare but serious condition that causes swelling in the liver and brain.

Taking a lukewarm -- not cool or cold -- shower, bath or sponge bath can also bring relief. You should rest when you have a fever, and drink plenty of fluids to stay hydrated. When any type of fever is persistent or becomes recurrent, it’s important to see your doctor.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My daughter had her gall bladder removed, and two months later she’s still suffering from watery diarrhea. She even had to be hospitalized to restore her fluids. What does your gall bladder do? Are there lifestyle or dietary adjustments that could help?

Dear Reader: The gall bladder is a small, pouchlike organ that is located in the upper-right quadrant of the abdomen, just below the liver and next to the pancreas. When distended, the gall bladder is about the size and shape of a small pear. Its job is to store bile, a complex digestive fluid that is made and released by the liver.

One of the roles of bile is to break down fatty foods into smaller components, including fatty acids. This is so that fats, along with fat-soluble vitamins, can be readily absorbed in the small intestine during digestion. Bile also aids in the elimination of certain waste products. Each time you eat fatty foods, your gall bladder contracts and squeezes a bit of bile into the small intestine.

Surgical removal of a gall bladder is known as cholecystectomy. These days, it’s most often a noninvasive laparoscopic procedure. The surgery can become necessary due to the presence of gallstones, which are hardened deposits that can form within the bladder. Gallstones may leave the bladder via the bile duct, a process that can be extremely painful. However, sometimes due to their size, quantity or position within the gall bladder, gallstones aren’t able to exit. They may block the bile duct, which can cause pain and lead to infection. Signs of gall bladder problems include abdominal pain and tenderness, excessive gas, chronic indigestion, fever, chills, nausea and jaundice.

The diarrhea that your daughter is experiencing is believed to occur in 10% to 20% of people who have had their gall bladders removed. The reason for it isn’t really clear. One theory is that, without the gall bladder to store bile, the increase in bile and bile acids within the intestines creates an environment that leads both to watery stools and increased muscular contractions. Basically, the excess bile and bile acids act as a laxative.

In most cases, this post-surgical diarrhea will resolve in the days and weeks following gall bladder surgery. In the short term, anti-diarrheal medications such as Imodium A-D may be used to get bowel movements under control.

Some people with this type of diarrhea find it helpful to eliminate caffeine, sweets or dairy products from the diet. If your daughter’s condition persists, her doctors may consider prescribing cholestyramine, a cholesterol medication that uses nondigestible resins to bind up the bile acids within the intestines. Due to the binding properties of cholestyramine, it’s important after a dose to wait four to six hours before taking other medications or supplements. Following a low-fat diet may help boost cholestyramine’s efficacy.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I was recently diagnosed with chronic venous insufficiency in both legs. What is it, and why does it happen? What does it mean for my health?

Dear Reader: One of the tradeoffs of the evolution of upright posture in humans is that at some point, the various fluids that circulate throughout our bodies face an uphill climb. This is particularly true of our blood, which gets pumped from a location high up in the body. Not only does it need to reach all of our tissues, but it has to complete a timely round trip back to the heart.

A branching network of arteries carry oxygenated, nutrient-rich blood away from the pumping chambers of the heart and out to the tissues via the capillaries. A similar network of veins return oxygen-poor blood and waste products back to the heart.

When you have chronic venous insufficiency, or CVI, it means that the deeper veins in your legs aren’t working efficiently to return the blood to the heart. This happens when the walls of the veins become weakened, and when the tiny one-way valves within the veins no longer function properly. These valves are an ingenious solution to the gravity fighting against the blood moving up from your legs back to the heart.

Working in concert with our muscles and with the smooth and elastic vein walls, these valves use a pair of opposing flaps to prevent the rising blood from ebbing backward between heartbeats. With CVI, the blood fails to make a consistent upward climb and pools in the veins. Blood pressure within the veins rises, which can damage both the veins and the valves.

Risk factors for CVI include age, family history, prolonged inactivity, pregnancy, obesity and being quite tall. CVI may also occur in people who have experienced deep vein thrombosis, which is a blood clot in the deep veins of the leg. Symptoms include swelling in the lower leg and ankle -- particularly after prolonged standing -- as well as aching, throbbing or tiredness in the legs. Skin on the legs and feet may itch, flake or appear leathery, and new varicose veins may emerge. The condition becomes more common after age 50, and is seen more often in women than in men.

Chronic venous insufficiency is not life-threatening; if ignored, however, it can lead to serious complications. These include leg ulcers, pulmonary embolism, deep vein thrombosis and secondary lymphedema, which is swelling in the tissues due to damage to the lymphatic system.

Depending on the severity of your particular condition -- there are varying degrees of CVI -- your doctor will outline strategies for you to follow. These can include being advised to lose weight, wear compression stockings, exercise regularly, elevate the legs, avoid prolonged standing and maintain skin care. Some patients benefit from nonsurgical treatments that use injected solutions or laser therapy to collapse certain smaller vessels.

It’s important for your health that you follow your doctors’ recommendations and make managing CVI part of your daily routine.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)