Recently, an acquaintance in the neighborhood was walking down the street when he suddenly collapsed to the sidewalk, stricken with a fatal heart attack. He was sixty years old. Whatever might have been going on in the spiritual side of his life, on the physical side of the coin, he was very overweight. At the very beginning of the year, another friend of mine didn't make it to Yom Kippur prayers because his blood pressured skyrocketted, and he had to be rushed to a hospital. Since then he's been on a serious diet to lose weight and eat healthier foods. Having learned his lesson, he exercises regularly and feels like he has been given a new lease on life.
Now that my beard has streaks of white, my doctor insists that I make periodical visits to a cardiologist. He also recommends a bi-annual blood test, a prostate check at the urologist, and a simple home examanation to see if there is any colonic bleeding, G-d forbid.
The Torah commands us to very carefully guard over our lives, repeating the word "maod" which means "very much." Therefore, when a person reaches the age where his beard begins to turn grey, he should make it a point to examine his health.
Women too. As a woman approaches fifty, she should go for the examinations and ultrasounds pertaining to women. Even at the age of forty, it doesn't hurt to make a routine, yearly visit to her gynecologist.
Please don't wait. How many tragic strories could have been avoided if people had simply been more precautious. While the teaching of our Sages is certainly true that it isn't the bite of the snake that kills, but the sin which led to it, one is not to test G-d by gambling with his life, by ignoring his health and the recommendations of doctors, thus neglecting a Torah command.
So be sure to eat healthy foods, get regular exercise, and don't put off important medical check-ups.
And be happy - that's the best medicine there is!