DEAR DR. DONOHUE: Recently, my granddaughter was diagnosed as bipolar. I am very concerned. I can’t find information on it. Is it inherited? Is it possible to live a normal life? Why did it show during her teenage years? She has just finished high school and was an honor student. Is there any support group? – A.B.

ANSWER: Bipolar disorder is a psychological condition that has some roots in genes, some in brain chemistry and some in life stresses. It’s a common illness, affecting between 3 percent and 8 percent of the population.

The two “poles” of bipolar are emotional highs and emotional lows. During the high periods, people need less sleep than usual. They have unbelievable reserves of energy. They are talkative and outgoing. None of this sounds bad, but in the extreme it is. During a “high” episode, people often make terrible decisions, act impulsively and take risks that can affect their health and futures. Thinking is disorganized, and hallucinations can develop.

During periods of the other pole – depression – all energy is gone. People take refuge in their bed and want to sleep all the time. They don’t want to interact socially. Concentration is difficult. Self-esteem flies out the window. Suicidal thoughts intrude upon the consciousness.

Brain chemistry is an elusive term, but one that figures greatly into bipolar disorder. Brain chemistry refers to messenger chemicals in the brain – dopamine, serotonin and others – that activate neighboring brain cells and transmit information between brain cells. In bipolar disorder, as in many other disorders, brain chemistry is upset. Medicines can often restore the right chemistry and keep the highs and lows on an even keel.

It’s not surprising that your granddaughter came down with the problem now. It most often strikes between the years of 17 and 18. With treatment, your granddaughter ought to do just fine. Many illustrious people with bipolar disorder have been outstanding successes.

The National Mental Health Association can provide you with more information. Its toll-free number is 800-969-NMHA. The Web site is: nmha.org.

DEAR DR. DONOHUE: Ever since I was a young child, I learned that a cut or any raw skin surface healed faster when it was exposed to air. My son says that at school, they told him it’s better to cover cuts and scrapes. Is that correct? – L.M.

ANSWER: It is correct.

You and I were raised in the same house. I was taught as you were. But wounds heal faster if they are kept moist. Covering them is the right approach.

DEAR DR. DONOHUE: I am a 79-year-old man and had been in excellent health all my life until the past year, when I began to suffer from weakness and loss of musculature. After six months of tests and doctors, it was discovered that I am severely lacking in vitamin B-12. A neurologist described my condition as treatable. I am now on a regimen of B-12 injections. Is there any chance of regaining the musculature I have lost? – G.W.

ANSWER: There is more than a chance. There’s every reason to believe you will.

Vitamin B-12 deficiency is the cause of pernicious anemia. Anemia is a deficiency of red blood cells. With any anemia, people lose their vim and vigor, and are unable to perform much physical exertion. That’s one reason why your muscles are weaker.

Pernicious anemia also features nerve damage. If treatment is delayed for too long, nerve function might not come back fully. However, with the neurologist’s statement that you are treatable, I understand that irreparable nerve damage has not occurred. Nerve damage could be another reason for your muscle weakness.

If you are like most patients, you can expect a full recovery.

You will, of course, have to start a strength-building program with the use of weights. Be sure to ask your doctor if your heart is up to such a program.

DEAR DR. DONOHUE: During my annual checkup, my doctor remarked about my mitral valve prolapse, which I have known about for a number of years. He also mentioned the possibility of pulmonary hypertension. I do have high blood pressure, but I am not familiar with pulmonary high blood pressure. What is it, and what causes it? – J.R.

ANSWER: The body has two blood pressures. The one recorded when doctors take arm blood pressure is the systemic blood pressure, the blood pressure created by the heart pumping blood into the general circulation.

The lungs have their own blood pressure. They are delicate structures and cannot tolerate the body’s normal blood pressure. Lung blood pressure is only one-fifth that of the body’s blood pressure. Hypertension is a rise of body blood pressure, and pulmonary hypertension is a rise of lung blood pressure. The two are not related, nor does a rise in systemic blood pressure cause a rise in pulmonary blood pressure.

In piecing your story together, I believe your doctor referred to pulmonary hypertension that could result from your mitral valve prolapse. The mitral valve is one of four heart valves. A prolapsing mitral valve is one that balloons upward when the heart pumps blood. Sometimes associated with the upward ballooning is a leakage of blood through the valve. If that occurs and if the leakage is great, it can raise lung blood pressure — pulmonary hypertension.

Symptoms of pulmonary hypertension are difficulty catching one’s breath, weakness, fatigue and sometimes chest pain. The ankles and feet might swell.

Your doctor must not think that your valve leakage is great, if indeed you have any, or that your lung pressure is dangerously high. He would have asked for more tests if he believed that. Pulmonary hypertension is something not to be taken lightly, and I can’t believe your doctor would leave you up in the air if yours were significant.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com