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Your Good Health: Fasting not needed for most blood tests

Dear Dr. Roach: My daughter is a registered nurse, and tells me that when getting blood tests, it is not necessary to fast eight to 12 hours even though my doctor says to do so. Four hours is enough, she claims.
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Dr. Keith Roach writes a medical question-and-answer column weekdays.

Dear Dr. Roach: My daughter is a registered nurse, and tells me that when getting blood tests, it is not necessary to fast eight to 12 hours even though my doctor says to do so. Four hours is enough, she claims. Is this true, or is my daughter trying to be a doctor, if you know what I mean?

L.C.

I probably agree with your daughter the nurse more than I do with your doctor in this case. Most routine blood testing does not require fasting. There is controversy about whether cholesterol testing is best done fasting or not: Most recent evidence suggests that fasting is not necessary. However, many physicians still continue to use fasting levels, as that is what they are used to. Nonfasting numbers might reflect the true state of risk to the arteries more so than fasting levels.

A few seldom-ordered tests, such as insulin levels, might need to be drawn precisely a certain period of time after feeding to be able to interpret them. In most cases, your daughter is probably right that prolonged fasting is unnecessary. I still recommend following your doctor’s orders. Your daughter is providing you with up-to-date medical knowledge. Any nurse or doctor should do the same.

Dear Dr. Roach: Can hypnosis bring a person out of depression?

J.C.A.

There is limited evidence that hypnosis, or hypnotherapy, is a potential treatment for depression. A 2010 study of 84 patients showed that approximately equal benefit of hypnotherapy compared with cognitive behavioral therapy, which is an accepted treatment for depression. I did not find a study comparing hypnotherapy with medication treatment. However, it might be worth considering hypnotherapy in someone with mild depression and no good response to other treatments or who is unwilling to use medication. I would not recommend hypnotherapy for severe depression.

For someone interested in this kind of therapy, finding a qualified therapist for hypnosis might not be easy. One suggestion is to look for membership in the American Society of Clinical Hypnosis or the Society for Clinical and Experimental Hypnosis.

Dear Dr. Roach: Do you recommend exercise after a stroke so that someone can make a comeback?

C.T.S.

A stroke is the name for damage done to the brain, usually by death of brain cells, and can be caused by lack of blood flow caused by a blood clot or by bleeding inside the brain. A transient ischemic attack is a very similar problem, only a TIA reflects a temporary issue (usually minutes or hours), while strokes last for longer periods. Strokes can involve very small areas of the brain, with loss of very specific function, or much larger areas with loss of motor control of an entire side of the body. Other kinds of strokes can affect other brain function besides muscle control.

For strokes involving loss of muscle control, exercise is a critical part of therapy after a stroke. Exercise should be begun soon after a stroke, whenever possible, and should be supervised by an expert. This is usually a physical therapist, often with an occupational therapist in addition. Frequent, precise, skilled physical therapy can sometimes make the difference between a person suffering residual problems and making much more complete recovery. Unfortunately, physical therapy cannot always bring about recovery, especially in a large stroke, although the brain does have remarkable ability to have other parts take over for the area of brain lost in a stroke.

Nearly all the benefit from exercise after a stroke will occur in the first year afterward, which is part of why starting soon is so important.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers can email questions to ToYourGoodHealth@med.cornell.edu