DEAR DR. DONOHUE: I am a healthy 27-year-old female. I was diagnosed as having osteomyelitis. I had severe pain and swelling on the ball of my foot. The orthopedic doctor treating me has little explanation to offer. My physician is adopting a wait and see attitude. What can you tell me about this problem? - K.M.O.

ANSWER: I'm a bit hazy about what you are asking. Is it, how do you get a bone infection? That's what osteomyelitis means, infection of the bone.You can get osteomyelitis in a number of ways. It can occur from a bone break in which a jagged bone edge penetrates the skin, where many bacteria reside. Or bacteria can enter bone by swimming there in the blood. However, that's not a common thing. Bacteria can, indeed, get into the blood easily, but usually they are quickly done in by the body's defenses. Some may elude those defenses.

Admittedly this is stretching for an answer. A more likely scenario might entail entry to the bone from an adjacent pocket of infection, for example from a deep skin abscess.

Often, osteomyelitis requires a prolonged course of antibiotics, but the treatment usually works. If this is not the case with you, then we must shift attention to chronic osteomyelitis. If that's the problem, write again, and we can discuss that separately.

DEAR DR. DONOHUE: How much recovery time should ordinarily be allowed following inguinal hernia repair surgery before resuming conjugal relationships without fear of aggravating the repair? - V.T.S.

ANSWER: The specific answer, of course, has to be what your own doctor advises. Otherwise, the general answer is that resumption of sexual activity ordinarily is OK as soon you feel comfortable enough.

You give me an opportunity to expand a bit for the many other readers who ask about recuperation from hernia surgery. There's a notion somehow that confuses inguinal (groin) hernias with genital tract problems. They aren't the same.

In men, the hernia can descend into the scrotum. It follows the path of the spermatic cord. But here, too, it is merely a matter of proximity, not direct contact.

In general, then, recuperation depends on the patient's general health and the kind of surgery done. Many return to work in two to three days and avoid strenuous activity for three to six weeks. But even that is not federal law. Some surgeons feel that is too long to wait. In surgery utilizing unbreakable non-absorbable sutures, the repaired tissue regains 70 percent of normal strength very quickly after surgery, permitting rapid return to activity within limits of comfort. But for you, or anyone, the attending doctor has the say.

DEAR DR. DONOHUE: I have never heard of sick sinus syndrome and would like to know something about it. - S.T.

ANSWER: I've wished for some time now that the name "sick sinus syndrome" could be changed. I know some people understandably might think of it in terms of nasal sinuses, with which it has nothing to do at all.

The sinus referred to here is the sinus node, the heart's pacemaker, whose electrical blips initiate each heartbeat.

You can imagine what happens when this sinus node "gets sick." The heart becomes unpredictable, suddenly slowing down and then suddenly speeding up without warning. During a slow heart phase, the patient may faint from sudden deprivation of blood circulation. Usually the cause of sick sinus syndrome is poor blood circulation to the node. In some instances, an artificial pacemaker has to be implanted to substitute for the natural one.