Dear Dr. Donohue • I was diagnosed with avascular necrosis in June of 2011. No one will help me or give me information on this condition. I cannot afford medical insurance. I am 68 and on a meager Social Security payment. Doctors refuse to take me as a patient. I need to know what the prognosis will be if this is left untreated. — C.S.

Answer • Avascular necrosis also goes by the name osteonecrosis. It indicates that a section of bone has died due to a loss of its blood supply. It's the bone's equivalent of a heart attack. Diabetes, prolonged use of cortisone drugs and illnesses like lupus, trauma and sickle cell disease are some of the ailments seen in association with it. In some people, a cause can't be found; it just happens.

If only a small section of bone is involved, the bone might regenerate in time. Patients often use crutches until that happens. For larger areas of bone, that section of bone collapses and becomes painful. Some intervention is needed. Removing the dead bone is helpful in healing. A procedure called decompression is favored by some doctors. Tiny holes are dilled into the bone to stimulate blood vessel growth. Replacement of an affected joint is another possibility. The hip joint is a case in point.

Have you explained your situation to Medicare? You're eligible for it. Do so. Call local hospitals to see if they sponsor clinics that provide services for minimum fees. You live not far from large cities with medical schools; contact them to inquire if they will accept your case. Call your county medical society and see if it can offer you help.

Dear Dr. Donohue • In March of last year, I was found passed out on the floor. When I woke up about a month later, they said I was toxic and had sepsis. What is that? — C.M.

Answer • Sepsis is invasion of the blood with bacteria that produce toxins (poisons). That's the "toxic" part. Bacteria find their way into the blood in many ways. They can enter the blood if there's a minor breach in the colon, which houses millions of bacteria. Or something like a boil can spread bacteria into the blood. Or a cut so minor that you paid no attention to it can allow bacteria access to the blood.

The bacteria and their toxins cause a profound drop in blood pressure. That's probably what landed you on the floor. Toxins can lead to the failure of important organs — liver, kidneys, heart and lungs. Septic shock, your illness, carries a high risk of death. Only through the intravenous infusion of antibiotics and medicines that keep organs alive and working do patients survive this harrowing and deadly illness. Whoever took care of you deserves praise for the wonderful outcome you had in the face of a lethal condition.

Write Dr. Donohue at P.O. Box 536475, Orlando, Fla. 32853-6475.