To your good health

Acute pain is usually due to an injury or infection, and we expect healing to occur relatively quickly. Chronic pain is expected to go on for at least six months. In some people, acute pain is not treated adequately at the time of injury, and the brain and body learn to be in pain chronically.

Fatty liver is an increasingly common problem. Risk factors include being overweight and having diabetes, high blood pressure and abnormal blood cholesterol levels.

Poison oak, ivy and sumac all have the same irritating oil, urushiol, which is one of the few substances that can cause a severe hypersensitivity reaction the first time a person is exposed to it. Repeated exposures are often worse.

Many antibiotics are associated with the acquisition of symptomatic C. diff infections, and although clindamycin is the best known, other antibiotics — quinolones, amoxicillin and related penicillins — are actually more common. The antibiotics kill off large numbers of healthy bacteria, allowing the unhealthy C. diff to take over.

There are many causes of chronic cough, but postnasal drip is at the top of the list. Dust mites are indeed a common allergen, and symptoms may include runny nose, watery eyes, sneezing and cough from postnasal drip.

Charcot-Marie-Tooth disease is the eponym given to a family of hereditary motor sensory neuropathies, diseases that affect the nerves that carry the impulses necessary for movement and sensation.

In general, doctors want all the information you can give. However, past medical history tends to become less important as people get older.

The menisci are ring-shaped cartilage structures that sit on top of the tibia and provide stability and shock absorption to the knee. Given the mechanism of injury and your prior history, a meniscal tear is a very likely possibility.

A solitary kidney mass in a man in his 60s is always suspicious for kidney cancer. A 2.4 cm tumor is large enough to provoke serious concern: In a recent study, in people who had their tumors removed, 83% of tumors that size were kidney cancer.

Before I get into why this story makes me both sad and angry, I want to address autism. Autism is an increasingly diagnosed condition that includes difficulty with social interactions, stereotyped repetitive movements and delayed language skills, although there is a subset of people with autism with no language delay.