Q. My hands and feet perspire profusely. What causes this? Is there any medication to help this condition?

A. Some people have excessive sweating of the hands and feet for no apparent reason, while others seem more sensitive to the factors that typically trigger sweating in the palms and soles -- excitment, social interation, mental or physical effort, anxiety or warm temperatures.

Known as hyperhidrosis, this condition commonly begins around puberty and tends to improve during middle age.

You can try topical applications of different solutions to help control troublesome sweating, but perspiration usually recurs when you stop the treatment. Your dermatologist may prescribe glutaraldehyde in a 10 percent solution to apply one to three times weekly to the soles of your feet. This causes a temporary brown discoloration that diminishes as you continue use.

For your palms, a 2 percent solution, available as Cidex, may help. It may be somewhat less effective than the 10 percent solution, but shouldn't stain your hands. However, some people find this substance irritating or unpleasant smelling.

Twenty percent aluminum chloride solution (Drysol) may also be effective. Oral medications, known as anticholinergics, may help, although they tend to cause drowsiness and dry mouth.

Finally, an electronic device called Drionic has helped some people. The device is availale only by a doctor's prescription and costs $100. It works by sending a mild electric current to hands or feet placed on small felt pads in a water bath. After about ten 20-minute treatments, some people's sweating decreases to acceptable levels for up to six weeks. For information write: General Medical Co., 1935 Armacost Ave., Los Angeles, Calif. 90025, or call: (213) 820-5881. Q. I was recently treated for phlebitis. My doctor didn't tell me if this is a recurring condition, but I suspect it will be as my leg is still swollen and looks the same as the day I started treatment. What causes phlebitis, and what is the outlook once you've had it? A. Phlebitis is inflammation of a vein. It's noteworthy because of its association with blood clots and potentially dangerous complications.

Phlebitis comes in two forms, superficial and deep. Superficial phlebitis causes localized pain, redness and tender swelling. It affects veins close to the skin's surface, mostly in the legs and occasionally in the arms.

Intravenous needles used to give fluids to hospitalized patients are common causes of phlebitis in an arm. Bacteria can gain entry to the vein through the needle and set up a mild infection, leading to phlebitis. Treatment includes removing the needle, using warm compresses and occasionally giving antibiotics. This condition usually doesn't lead to serious problems.

A minor, often unnoticed, injury or skin infection can cause superficial phlebitis in a leg. Varicose veins are also prone to develop phlebitis. Treatment includes warm compresses, pain relievers and sometimes antibiotics. Full recovery is the rule.

The situation is different for deep phlebitis, often called thrombophlebitis or deep vein thrombosis, meaning blood clots in the veins deep within. This condition usually occurs in the veins of the legs and pelvis, producing dramatic, often painful, swelling. It's caused by sluggish circulation (as with prolonged bed rest), damaged veins (as in a fractured leg) or increased tendency of the blood to clot (as occurs during pregnancy or while taking birth control pills or estrogen hormones).

Deep phlebitis can be serious, even fatal, because blood clots in the legs can travel to the lungs, where they plug up circulation and keep oxygen from getting to the bloodstream. Known as a pulmonary embolism, its symptoms are sudden shortness of breath, sometimes with chest pain.

Treatment of deep phlebitis includes hospitalization for about 10 days to get a blood-thinning medicine called heparin, followed by an oral blood thinner called Coumadin after leaving the hospital.

Even with treatment, deep phlebitis often permanently damages the veins' check-valves, which aid in proper circulation. Loss of this function leads to chronic swelling in the legs, which you seem to have developed. Treating this complication can be difficult, and you may need special support stockings to keep the swelling down. Q. Can you provide any information about a vaccine for chicken pox? As a 37-year-old mother of two preschool children, I'm very interested. None of us has ever had chicken pox. While I realize it usually isn't a problem for children, I'm concerned for myself. A. A vaccine for chicken pox has recently been developed and will become available in the next year or so, but you probably won't need it. The reason is that most adults have picked up immunity to chicken pox over the years, even if they don't remember having had the disease.

Every once in a while, however, an adolescent or young adult will come down with chicken pox, and it can be very bothersome or dangerous, sometimes causing serious pneumonia. In very young women who are pregnant, this can threaten the life of both mother and baby.

But the people who will benefit most from the chicken pox vaccine are those young persons whose natural immunity is weakened by serious disease or medications such as cancer chemotherapy. This is the group likely to suffer the most serious consequences of chicken pox infection and for whom prevention is important.

As yet, however, the Food and Drug Administration has not approved guidelines for vaccine use or the persons eligible to receive it.