When Otto Graham gave up his job as general manager and head coach of the Washington Redskins in 1969, he was a healthy, strapping fellow who looked every inch the football Hall-of-Famer he was.

Just a few years later, he lay wasted and wan, fighting for his life on an operating table, the victim of advanced colon cancer, an insidious disease that spreads slowly but gives few early warning signs other than slight bleeding that generally is well hidden within the bowel movement.

No one can say precisely when it started, but by the time Graham's disease was diagnosed in 1978, it had progressed to a Dukes C designation -- the advanced stage in which the cancer has broken through the bowel and started to invade the rest of the body.

Graham was one of the lucky ones, though: thanks to radical surgery, which included removal of his colon, he survived.

"But," he recalls wryly, "I could have saved myself a lot of grief if I had been tested, or tested myself, for occult [hidden] blood every year, as doctors recommend.

"We might have caught the cancer much earlier, my surgery wouldn't have been as radical, and I could have avoided a colostomy and the way that procedure affects your life style."

Graham's case was not unique: 130,000 new cases of colorectal cancer are diagnosed, and 60,000 Americans die of the disease, each year. But, most doctors agree, 40,000 of those lives could be saved if the disease were detected earlier.

A major tool in the early detection of colorectal cancer is the home test -- a simple procedure marketed by several companies that allows an individual to screen for hidden blood in the stool.

This is one of an increasing number of do-it-yourself health tests that allow people to screen themselves for a variety of conditions -- from strep throat to the cause of impotence to cancer -- in the comfort of their homes.

Annual sales of home health tests have grown from $200 million in 1981 to $384 million last year, according to Frost and Sullivan Inc., an international market research organization for the health industry. The firm predicts annual sales will reach $736 million by 1989.

This is a healthy trend, assert some medical authorities. Patients who conduct their own health screening tests may not only save time and money -- they also might save their own lives.

One of the most outspoken advocates of home testing is Dr. Edward R. Pinckney, a Los Angeles-based internist and author, with his wife Cathey Pinckney, of "Do-It-Yourself Medical Testing," a catalogue of 165 home health tests that can be performed with equipment now available.

"Home medical testing can improve health care for countless millions of Americans at the same time it significantly reduces the cost," says Pinckney, a former editor of the Journal of the American Medical Association and former chairman of the Department of Preventive Medicine at Northwestern University Medical School.

"By detecting the earliest warning signs of disease, home testing can alleviate untold human suffering. In sum, it has the potential to save tens of thousands of lives each year."

Concern about the increased use of home tests and the appropriateness of making certain types of tests available to consumers has prompted the Food and Drug Administration to schedule a public meeting on the topic early next month. If some tests are not used properly, FDA associate commissioner Alexander Grant notes in an announcement of the meeting, "false or misleading readings could result in adverse health consequences."

Home health tests have come a long way since Miles Laboratories brought out the first do-it-yourself test -- a simple urine test for diabetics -- in 1941. Among the most common are urine tests for a wide variety of conditions from ovulation to urinary tract infection. Home blood tests for conditions such as anemia, mononucleosis and diabetes are common, too.

A variety of low-cost diagnostic hardware also is available, ranging from a simple $5 device that takes the place of a $200 pulmonary function test, recommended for those with respiratory conditions and for the elderly, to digital blood pressure cuffs costing as little as $39 that Pinckney says every family should have.

And in the near future are a whole new generation of tests that could prove even more accurate -- because the results will be read by built-in computer chips.

These "smart test tubes" will remove much of the personal element from reading test results, Pinckney says. The microprocessor chips will analyze a body fluid, light up if there is anything to detect, and stay lighted long enough to be examined by a doctor.

Home tests now available enable you to:

Check your bowel movements for signs of hidden blood -- an early symptom of colon cancer -- by dropping a piece of chemically treated paper in the toilet, or spraying a stool specimen and paper surrounding it and watching to see if it changes color.

*Analyze your own blood -- if you're not too squeamish to prick your finger for a sample -- to test for a variety of conditions, including anemia, diabetes, kidney function and mononucleosis.

Use chemically coated plastic strips to conduct 11 different urine tests to detect everything from recurring urinary tract infections to serious liver and kidney problems.

This so-called dip-stick urinalysis technique can provide major benefits for women suffering recurring urinary tract infections (up to 8 million have them on any given day, reports The New England Journal of Medicine) by detecting them early, when they can be cured by a single dose of antibiotic. And it can detect pregnancy as early as three days after a missed menstrual period, so women can avoid prescription drugs, alcohol, tobacco, or X-rays, which could cause damage to the developing fetus.

Home urine testing also provides major benefits to diabetics, Pinckney says, citing a 1979 University of Southern California study that says the tests can reduce the danger of diabetic coma by 70 percent and the number of emergency room visits by 50 percent.

One new dip-stick test uses monoclonal antibodies -- a product of genetic engineering -- to tell women when they will ovulate up to 36 hours in advance. This eliminates the tedious, complicated and sometimes inaccurate procedure of trying to predict ovulation with a basal thermometer.

*Monitor your blood pressure regularly with a new digital device, which could identify undiagnosed hypertensives and save hundreds of dollars a year in unnecessary drug charges and side effects for millions more who have been diagnosed mistakenly.

*Test for allergies by taping the suspected allergen next to your skin with an ordinary Band-Aid and leaving it there for two days -- which may reveal the cause of headaches, stomach problems, rashes, wheezing and even personality changes.

*Determine if impotence has psychological or physiological roots by using a device that detects erections during sleep.

New tests coming into the marketplace include:

*A test for strep throat that could save the lives of as many as 10,000 Americans every year, based on statistics compiled by the American Heart Association.

If not diagnosed and treated quickly, strep throat can become rheumatic fever, which can leave the patient with a crippling and sometimes fatal heart condition.

Until recently, strep could be diagnosed only through a culture taken by a doctor and sent to a commercial laboratory -- a process that took at least 24 hours. Results of the new home test are available in minutes.

*A chemical test to detect sulfites -- preservatives used in the production of wine and some processed foods -- and sometimes sprinkled on foods by restaurants to keep them fresh-looking. The Food and Drug Administration has proposed a ban on the use of sulfite preservatives by restaurants, but not on processed foods or beverages. "The problem with sulfites is that if you have asthma," Pinckney says, "they can cause a deadly reaction known as anaphylactic shock."

*A saliva test for alcohol. Within a year or two, a team of scientists at the Addiction Research Foundation in Toronto say they will release a chemical dip-stick that can give a precise measurement of alcohol content in the blood simply by exposing the plastic strip to saliva.

*A home glaucoma test. Scientists at Northwestern University and University of Illinois Schools of Medicine have developed a home-testing device that they say could help save the eyesight of tens of thousands of Americans. Known as the "self home tonometer," it registers eye pressure and is used by the patient about five times a day for three to six days. The physician then interprets the pressure readings.

Does this trend mean health care is being taken over by do-it-yourselfers?

"Emphatically not," says Pinckney. "Used properly -- and preferably under a doctor's supervision -- home screening should result in detection of symptoms much earlier than has been possible in the past."

Other doctors are less enthusiastic. Some, while conceding the potential benefits, also warn of the danger of patient error in conducting tests and interpreting results.

One, Dr. Bryce Bliss, director of laboratories at Tulane University Medical Center, warns:

"Patients can benefit from home testing; I wouldn't want to discourage it. But it needs to be done with tremendous caution. The dangers are from false readings, caused by patient carelessness, outdated chemical tests, or from environmental interference such as diet or medication.

"And obviously the results should be studied by a physician."

Home tests also have the potential for disaster.

For example, Pinckney says: "If a woman is testing herself for pregnancy and fails to follow the directions, takes the test at the wrong time or neglects to confirm the results by doing the test a second time, she could get a false negative -- and that could be disastrous. If she were to have a series of diagnostic X-rays done after getting a false negative on a home pregnancy test, it could result in terrible damage to her baby. If she were to take a new drug such as Accutane an acne drug , for example, it would result in fetal damage."

Sometimes the tests themselves can be defective. SmithKline Diagnostics, maker of the Hemoccult tests for blood in the stool, last week recalled 90,000 bottles of the chemical used by doctors to read the test.

In this case, the home version of the test was unaffected. But problems could occur with the home test if a patient "was too squeamish to place the test paper firmly and precisely against the anal entrance so as to get a good specimen," Pinckney says, "that could result in a false negative."

"And that conceivably could cost the patient his or her life."

Home testing is "a question of common sense," says Dr. William H. Wehrmacher, professor of medicine at Loyola University's Stitch School of Medicine. "Within limits, home testing can be a good thing, but it requires balance; you can push anything to the point it becomes preposterous -- and some patients will."

"Home tests can be dangerous, even deadly, if you don't follow the rules," Pinckney warns. "But those rules are fairly simple:

*"Check the expiration date on the box if you're using a chemical test; if it's out of date, don't buy it, because it could give you a false result.

*"Read the directions several times to make sure you understand them, and then follow them religiously, as though your life depended on it -- because it could.

*"Take the test more than once to confirm the results -- you can't trust a single result because you might have made a mistake.

*"A false positive, a test reading that indicates occult blood in your stool, for instance, isn't terribly dangerous -- though it could be very nerve-racking -- because it simply will send you racing to your doctor.

"But a false negative could lull you into a false sense of security and prevent you from seeing a doctor when you should. That could be lethal."