DEAR DR. ROACH: I’ve been going to chiropractors for 30 years. They help me when I have a pinched nerve, but they always want me to keep coming back. How do I know whether that exacerbates the problem? It seems to me that it may loosen things up so I have to keep coming back. -- S.B.

ANSWER: Chiropractic spinal manipulation is considered a generally safe treatment for lower-back pain, and it is associated with some benefits in pain and function.

There remains controversy about rapid manipulation of the cervical spine in the neck, with rare reports of stroke following this procedure. It is not clear whether the apparent risk of stroke is due to the manipulation, or whether people with symptoms of a dissection happen to see a chiropractor, making an apparent connection when there is none. I am conservative and recommend against rapid neck manipulation, which is a plausible cause of damage to the arteries in the neck.

I do not believe that the manipulation of the lower spine for treatment of back pain causes problems that would require further treatment. I believe that chiropractors, like traditional medical doctors, truly want to help their patients, and offer follow-up appointments when they think they can be helpful. However, like any therapy, I would recommend against it if it isn’t clearly helping.

DEAR DR. ROACH: Please tell me why I bruise at the slightest pressure? I’ve been on gamma globulin for CVID for seven years. Is there any correlation? -- M.M.S.

ANSWER: CVID, common variable immunodeficiency, is an inherited disease of the immune system that I discussed in a column earlier this week. People with CVID are more likely to get certain infections, such as sinus infections, pneumonia and bacterial gastrointestinal infections. People with CVID have lower amounts of antibodies, also called immune globulins, so a common treatment for CVID is to boost immune globulins by injection, especially intravenous immunoglobulins. These are obtained from blood and plasma donors, and provide some protection against infection. CVID should be considered in people with recurrent infections. People with CVID have low blood levels of immunoglobulins, especially IgG, also called gamma globulin. People with Type 1 or Type 2 diabetes seem to have a high risk of CVID.

Bruising is not a common side effect with intravenous immunoglobulin, IVIG. The package insert says that it happens less than 4 percent of the time; however, I found many people in online forums noting this effect. Easy bruising can be a sign of platelet conditions, so it may be worthwhile to get that checked by your doctor.

DEAR DR. ROACH: I have high blood pressure, for which I currently take 10 mg of lisinopril. I had a transthoracic echocardiogram done, and “mild concentric left ventricular hypertrophy” was listed on the results. What does that mean? -- D.K.

ANSWER: The left ventricle is the chamber of the heart that squeezes blood to the body (rather than to the lungs, which the right ventricle does). “Hypertrophy” means that the muscle of the ventricle is thicker than normal. “Concentric hypertrophy” means the thickening is symmetric, and that is most commonly seen in people with high blood pressure, especially if it wasn’t caught early or was not treated well for some period of time.

Lisinopril is generally a good treatment for most people with concentric LVH, but some people need additional treatment. Many physicians, including myself, try to get the blood pressure down into the 120/80 range in people with LVH, as long as they can tolerate the medication.