How you can rein in health care bills — yours and society's.

Our carbon footprints are calculations of the greenhouse gases we're individually responsible for. Reduce yours, and you can take some satisfaction in having done something, however small, to reduce emissions and slow global warming.

Now might be a good time to start thinking about our health care footprints. Reforming health care and extending medical insurance to all Americans have become national priorities, despite — or maybe because of — the weak economy. But those efforts are likely to founder unless spending on health care is brought under control.

Serious reform and ...

In brief The shoulds — and the shouldn'ts — of getting your shots Vaccination used to seem simple and straightforward: the annual flu shot, the tetanus booster, a few others. Besides, vaccines were mainly for kids.

Now, like everything else, vaccination has gotten a great deal more complicated. The number of FDA-approved vaccines has grown from nine in 1980 to an unwieldy 17. A dozen of them are on the adult schedule, although several (the hepatitis A and B vaccines, for example) are reserved for high-risk groups.

American vaccine policy is set by the Advisory Committee on Immunization Practices (ACIP), ...

CT scans can speed a diagnosis and make it more accurate, but there's also cost and radiation to worry about.

The economy is in a downturn, but these are boom times for medical imaging. Old-fashioned film x-rays have their place. Doctors still x-ray bones to see if they are broken and order chest x-rays to diagnose pneumonia. But now radiologists — doctors that specialize in making diagnoses from medical imaging — have plenty of other ways to peek inside the human body to get a picture of what's going on. Magnetic resonance imaging (MRI) produces brilliant images of the brain, ...

The abdominal fat we put on in middle age may wind up causing dementia when we're older.

The woes that can arise from being overweight are pretty familiar by now: high blood pressure, diabetes, heart attacks, strokes. Less well known, perhaps, are the cancer risks. Heavier people have higher rates of colon, kidney, pancreatic, and postmenopausal breast cancer.

Now there's another consequence to be worried about. Over the past several years, researchers have slowly accumulated evidence linking excess weight to dementia. The dossier includes results showing a correlation between heaviness in middle age and dementia that develops decades later. It ...

Q. Within a three-month period, both my sister and her husband (both in their 40s) were hospitalized with pulmonary embolisms. Any thoughts on the cause? Could it be something in the air?

A . A pulmonary embolism is a blood clot (or a piece of one) that forms somewhere in the body, usually the veins of the legs, gets loose, travels through the bloodstream, and lodges in an artery in the lungs. The consequences are extremely variable, ranging from no symptoms at all if a small clot blocks a small artery to sudden death if a large one blocks a ...