Harvard Health Content API

A variety of disparate factors can speed up people’s biological aging, which describes how well their body functions (in comparison to chronological aging). Drivers of aging include ultraviolet light, stress, smoking, obesity, radiation, and loneliness and social isolation.

Most people with early-stage Lyme disease symptoms develop a rash, but it often lacks bull’s-eye features—which many people have been told to look for. Other signs of Lyme disease include headache, neck pain, joint aches, and fatigue.

Full-body MRI scans are marketed as a way to detect hidden cancers and other health conditions before symptoms appear. But these elective scans aren’t as precise as medically recommended MRIs and may reveal harmless abnormalities that lead to unnecessary follow-up tests.

Women’s reproductive history, including first period, pregnancy, and menopause, influences their lifetime exposure to estrogen, which appears to shape brain aging and dementia risk. Menopause is believed to be the strongest reproductive factor, with later menopause tied to lower dementia risk.

It’s possible for people of any age to contract sexually transmitted infections (STIs). STIs are sometimes symptom-free, making them easy to miss, pass along, and ignore.

Pain from gallstones (hardened, stonelike lumps of bile or other digestive fluids that block bile ducts) usually occurs in a distinct pattern. Gallstone attacks typically provoke steady, intense pain in the upper right abdomen that can radiate to the shoulder or back.

MRI contrast dye is widely used and considered safe. It helps highlight blood vessels, tumors, and other structures to improve diagnostic accuracy. Rarely, contrast dye can trigger a serious condition called nephrogenic systemic fibrosis in people with advanced kidney disease.