HEALTH ON THE TUBE

Here are the week's health program highlights on TV: TODAY Here's to Your Health. Aging: How to Die Young as Late As Possible.Discussion of ways to extend mental and physical vitality into oldage. 8:30 a.m., Channel 20. Medicine at the Crossroads. This eight-hour miniseries exploringthe impact of the medical revolution opens with a look at JohnsHopkins' success treating serious disease and the barrier separatingpatients from their doctors. 9 p.m., Channel 11. TUESDAY Doctor Is In. 10 a.m., Channel 20. WEDNESDAY Here's to Your Health. For Relief Of . . . Take Two. A discussionof headaches and their causes. 8:30 a.m., Channel 20. THURSDAY Your Baby and Child. Gender identity in children. 7 a.m., Lifetime. FRIDAY Accent on Health. 12:30 p.m., Channel 38. Doctor Is In. A day in the life of two family practitioners. 1p.m., Channel 11. Aging of America. The Dilemma of Long-Term Care. Why few Americanswill be adequately prepared for long-term health care. 9 p.m.,Channel 20. SATURDAY Every Breath You Take. Walter Cronkite and Joan Lunden hostdocumentary that will view lung disease through the eyes of itsvictims. 1 p.m., Channel 2. SUNDAY American Baby. How children are affected by birth order;differences between sexes; forcasting for the future. 10 a.m., FamilyChannel. Healthlink. 10 a.m., Lifetime. Healthy Kids. Learning disabilities; stepfamilies; parents who wantto know. 10:30 a.m., Family Channel. This Week in the New England Journal of Medicine. 11 a.m., Lifetime.