DEAR DR. DONOHUE: Some of my co-workers asked me to ask you how to get blood pressure down, especially the second number. What do these numbers mean, exactly – the above and the below numbers?

My fellow workers are on a diet and try hard to get their numbers down, but nothing seems to work. Help. – S.F.

The first number (the “above” number) of a blood pressure reading is the systolic (sis-TAL-ik) pressure. It’s the pressure imparted to blood when the heart muscle squeezes blood out of the heart and into arteries.

The second number (the “below” number) is diastolic (DIE-uh-STAL-ik) pressure, the pressure that remains in blood between heartbeats. If you hook up a hose to a faucet and suddenly turn the faucet on and suddenly turn it off, water gushes when you turn it on – systolic pressure – and water continues to flow out of the hose after you turn the faucet off – diastolic pressure.

Both numbers are important. If either number is above the normal value, that’s high blood pressure – hypertension.

A first number of 140 or higher, a second number of 90 or higher or elevations of both numbers constitute high blood pressure.

Normal blood pressure is a reading of less than 120/80. Pressures in between those two values are called prehypertension – not high blood pressure, but the next step to it.

You lower blood pressure by losing weight, by exercising regularly, by cutting way back on salt and salty foods, by moderating the amount of alcohol drunk (two drinks a day or less for men, and one for women) and by eating mostly fruits, vegetables and grains.

If these things don’t bring pressure down, then people must take medicines to lower it.

Untreated high blood pressure leads to heart attacks, strokes, kidney damage, artery hardening and early death.

Hypertension is one of North America’s biggest health problems.

The booklet on it explains it and its treatments. Readers can order a copy by writing: Dr. Donohue – No. 104, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Let us talk about enemas. How many are too many? How many are harmful? What is the difference between enemas and high colonics? – V.G.

One enema is too many if it’s not needed. Two are too many if one gets the job done. Enemas have a place in medicine, but that place is not a large one.

They’re used to remove impactions, hard stool that has blocked the lower colon so feces cannot exit it.

They should not be used for ordinary constipation or, if they are, they should be used infrequently. Overuse irritates the colon, causes the body to lose electrolytes (sodium, potassium chloride and bicarbonate) and interferes with normal colon muscle contractions.

High colonics are administered through a tube placed far up into the colon (the large intestine, the large bowel) through the rectum.

Through the tube, large volumes of fluid are introduced into the colon.

High colonics can be dangerous.

They can perforate the colon. They can promote infections. In my opinion, they have no medical justification.

DEAR DR. DONOHUE: In winter in cold climates, is it really necessary to take a shower daily? Does showering daily promote better health?

Until 75 years ago, not many homes had a bathroom or a shower, and for centuries before that, taking a bath was uncommon. Is it really important to shower daily if one doesn’t perspire? – E.F.

It’s not necessary to shower daily.

It’s necessary to shower when the body gets dirty or develops an aroma of overripe fruit.

Once a week was enough for our ancestors, and for quite distant ancestors, bathing was even less frequent. Their health didn’t suffer. On the other hand, if you do get dirty daily or if you do sweat much, then a daily shower keeps the germ population of the skin to a minimum.

It is necessary to wash hands frequently every day to rid them of germs that can enter the body or be passed to others.

DEAR DR. DONOHUE: Three years ago I had a hip replacement, and have lived in daily pain since the operation.

I have to use a cane even in my home. I have had six shots, chiropractic adjustments and pain patches, but none has given me relief from constant pain. My surgeon finds nothing wrong on X-rays. Any thoughts? – K.S.

The X-rays might be fine, but the hip isn’t. If your surgeon can’t give you an explanation, seek another orthopedic surgeon.

The pain has to be coming from something that’s not right. You shouldn’t have to live with it.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from