About 20.8 million people have diabetes with up to 95% of those having type 2 diabetes; 41 million are at risk with pre-diabetes. Could it be you?

A lot of people have diabetes and don't know it, but the symptoms will eventually catch up with you.

Watch out for extreme thirst, dry mouth, increased urination and blurred vision. These are often the first signs of diabetes.

Type 2 diabetes is related to insulin resistance, when the body is unable to properly use insulin hormone to control blood sugar levels.

If you have any of the early symptoms, get either a urine or a fasting blood sugar test to find out where you stand. Controlling blood sugar is vitally important in reducing the risk of heart attack and other complications.

Testing for diabetes should be considered every three years beginning at age 45, according to current guidelines. And even more frequently in people at increased risk for the condition.

People at highest risk for the disease are those who are overweight, women who developed diabetes during pregnancy (gestational diabetes), and people with family members who have the disease.

Heart disease is public enemy No. 1 for men and women. Often, the first sign of a heart attack is not crushing chest pain like we see in the movies, especially for women.

In women, signs of a heart attack may include bloating, gastrointestinal upset, back pain, arm pain, nausea and sweating.

And chest pain is often not a sharp pain, but a very dull, achy heaviness.

You may not even have chest pain. Instead, you may feel fatigue, sweaty, nauseous, or winded. If you feel such symptoms, you may not be sure what's wrong. They may even come and go, but to be on the safe side, you should call 911 immediately to seek care.

Regular exercise, eating a healthy diet and not smoking can help lower risk of heart disease and heart attack. A daily baby aspirin may also be advisable to lower your risk, provided you have no history of ulcers or liver problems. Talk to your doctor before taking aspirin to lower your heart disease risk.

It's not only common, but recent studies demonstrate that herpes cuts across race and class very dramatically.

Yet early symptoms are so subtle that people often don't recognize them as a problem. The key is knowing what to look for.

About two-thirds of people with genital herpes will eventually recognize some symptoms. If you have recurring symptoms below the belt that are unexplained even those that you may think are yeast, dermatosis, or even hemorrhoids consider getting tested for herpes.

If you think you may have symptoms, testing makes sense because if it's herpes, we can promote appropriate prevention steps. For example, an infected person can take antiviral drugs daily to reduce the chance of passing the virus on to a partner. Condoms also greatly reduce the risk but do not eliminate transmission.

Melanoma accounts for 4% of all skin cancers, but causes nearly 80% of the deaths. When was the last time you checked your skin?

Go to a board certified dermatologist at least once a year for a full body screen. If you catch it early, it may just be an atypical mole and not a melanoma yet. And if it's a melanoma, it may be a thin melanoma on the top layer of the skin.

Skin checks are particularly important for Asian-Americans, African-Americans and Latin Americans. In these populations, melanomas may not be in sun-exposed areas. We find them in the mouth, under the finger- or toe-nails or in the genital areas. These hard-to-spot places need to be monitored in all people, but particularly in these ethnic groups. Dermatologists recommend you check yourself monthly at home to look for irregular lesions that are growing and changing.

Look for these ABDCs in moles:

    Asymmetry or moles where one half is different than another
    Border Irregularity, meaning that the edge of melanomas are usually ragged and jagged
    Color because melanomas often have a variety of colors within the same mole
    Diameter as melanomas continue to grow

To prevent melanoma, the American Academy of Dermatology recommends avoiding sun exposure from 10:00 a.m. through 4:00 p.m. when the sun is the strongest. You should also wear a broad-spectrum sunscreen and reapply it frequently. Wear a hat and clothing with a tight weave that will block ultraviolet light.

It's important to know that high blood pressure can affect you at any age including young people and adolescents.

There's a reason high blood pressure is called the silent killer! One in four American adults has high blood pressure, according to recent estimates. But because there are no symptoms, nearly a third of these people don't know it.

The only way to tell if you have high blood pressure is to have your blood pressure checked. Your doctor should check your blood pressure at every visit. The upper number in a blood pressure reading (systolic pressure) should be less than 120 and the lower number (diastolic pressure) should be less than 80, according to the American Heart Association.

Uncontrolled high blood pressure can lead to stroke, heart attack, heart failure or kidney failure. But there's a lot you can do to help keep your blood pressure in check.

For one, a low-calorie, low-salt diet is key. Salt causes the body to hold fluid in the vessels, which increases blood pressure automatically.

Exercise is really, really important. During aerobic exercise, the body releases [feel-good chemicals called] endorphins that have a positive effect on widening blood vessels and decreasing blood pressure.

Stress reduction is also vital. Stress causes constriction of blood vessels and that increases blood pressure. Smoking increases blood pressure and one of the first things people can do is to quit smoking and try to avoid passive smoke.

If lifestyle changes don't work, your doctor can also prescribe medicine to help lower moderate-to-high blood pressure.

Glaucoma is a painless, gradual loss of vision.

About 2.5 million Americans have the most common type of glaucoma -- primary open-angle glaucoma. But half may be unaware that they have this potentially blinding disease because they have no symptoms, according to the American Academy of Ophthalmology.

It generally affects peripheral vision first; constricting it so slowly that you don't know that you are missing it.

You can lose a significant amount of vision before you know you have it. In glaucoma, the optic nerve is damaged. It can be associated with elevated pressure inside the eye and can lead to vision loss. It is ranked as the second leading cause of blindness in the U.S.

There is good news: Early diagnosis and treatment can preserve your sight.

In the majority of folks, if you catch it early and lower intraocular pressure, you can slow its progress so that the typical person won't have problems during their lifetime. Typically, an eye doctor will prescribe eye drops to lower eye pressure. Surgery is also an option if needed.

Risk factors include family history of glaucoma, African-American descent, increasing age and elevated eye pressure. We can treat eye pressure to lower it and reduce risk of vision loss, but most of other risk factors we can't change.

Your best bet: If you have glaucoma, get a field of vision test once a year. More frequently, if the condition is advanced. If you are at risk and your pressure is normal and your visual field is normal, you may not need to get tested every year but should be followed by an ophthalmologist.

About 105 million Americans have total cholesterol of 200 mg/dL or higher, the level at which the risk for heart disease begins to rise.

High cholesterol is a major risk factor for heart disease, yet it has no symptoms. Most people don't know their cholesterol is too high unless they get a blood test as part of their annual physical.

Knowing your cholesterol good and bad is important, DO, an internist at the Arizona Heart Hospital in Phoenix. From there, try to decrease the bad and increase the good.

“Bad" or low density lipoprotein (LDL) levels should be less than 130 milligrams per deciliter of blood (mg/dL) with optimal levels less than 100. The lower the LDL, the better. . "Good" or high density lipoprotein (HDL) levels should be 40 mg/dL or higher.

The American Heart Association recommends having your cholesterol levels measured every five years -- or more often if you are at increased risk.

What's the best way to get your cholesterol numbers where you want them?

Eat foods low in saturated fat and cholesterol, lose weight if you need to and exercise. Lifestyle changes can lower your cholesterol and reduce your risk of heart disease and stroke. If these changes are not enough, ask your doctor about medicines to lower cholesterol.

Like red-light warnings on the dashboard, the human body sends out a flare when something's awry. Chest pain, shortness of breath, dizziness -- those are some familiar medical symptoms. But other problems can creep up on you, too -- aches and pains, lumps and bumps. When are they important, when are they not?

The symptoms are killing way too many people. There's tremendous suffering and horrible death which could be avoided, but people don't know that something's wrong. In fact, it happens all the time, a symptom is missed -- and it leads to a tragic ending. Or it's caught just in time, and a life is saved.

Here are "six flags" -- six medical symptoms -- you should keep in mind:
    If you have unexplained weight loss and/or loss of appetite, you may have a serious underlying medical illness.

If you're on a diet, you're expecting this to happen. But if you're eating the same way -- and now have to adjust your belt a few notches tighter -- you could have a serious problem.

With ovarian cancer, the opposite is true. Fluid builds in the abdomen, and women think they are gaining weight. But if you have been at the same weight range for years, and doing nothing different, see a doctor.

    Slurred speech, paralysis, weakness, tingling, burning pains, numbness, and confusion are signs of a stroke, and you should get to an appropriate emergency center immediately. Early treatment may prevent permanent damage to the brain or even save your life.

Slurred speech can often go unnoticed. However, you might have a blood clot in a blood vessel going to the brain or bleeding in a blood vessel.

    Black, tarry stools may indicate a hemorrhage from an ulcer of the stomach or the intestine. It is important to stop the bleeding and to rule out cancer as a cause. What you eat changes the color of stools. But black, tarry stools mean there may be bleeding higher in the intestine. It could be a sign of a bleeding ulcer or cancer in the intestine.

    A headache accompanied by a stiff neck and fever is an indicator of a serious infection called meningitis.

In fact, if you can't put your chin on your chest, that's a sign you may have bacterial meningitis. You need antibiotics immediately to kill the bacteria before it infects and scars the brain.

    A sudden, agonizing headache, more severe than any you have felt before, could mean you are bleeding in the brain. Go to an emergency room immediately.

A brain aneurysm is rare, but it can happen -- even in people under 40. It can be very disastrous if it's not treated. If you have a severe, crushing headache, you may have an aneurysm, which is a blood-filled pouch bulging out from a weak spot in the wall of a brain artery. If treated before it bursts, it could save your life.

    For women: Vaginal bleeding after menopause is a waning sign of possible cancer. Some women are in denial when they discover postmenopausal bleeding. Others think it's a little cut, or something in their urine. But bleeding after menopause is a sign of uterine cancer, which is treatable if caught early.

    For men: A lump in your testicle with or without a small lump in the groin could be serious. Testicular cancer is more commonly found in testicles that did not naturally descend from the abdomen to the scrotum.

It's an old, old saying: The squeaky wheel gets the grease. But it's vitally important in medicine. If you know something's not right with your body -- if you've got that severe, crushing headache, but doctors aren't taking it seriously -- stand up for yourself.

Tell doctors you know it could be a problem – “I want you to rule this out," you should say. If they balk, here's your line: "I want you to write on the chart that you refused to do proper tests." Doctors are human; they get tired and distracted. It helps to get extreme, to get their attention. Sometimes you have to make a scene. The one person most likely to be concerned about whether you live or not is you. You have the greatest empathy for yourself.

All adults -- from senior year of high school and up -- should be familiar with standard medical symptoms, to help them preserve their good health.