Harvard Health Blog

It's hard to accurately predict when new viral outbreaks will appear or old viruses will reappear and how to figure this out quickly enough to respond quickly. Wastewater testing, a tool that can help predict upticks in COVID cases, has also captured evidence of infectious diseases like polio, allowing preventive measures to be taken.

After a man has had a radical prostatectomy, sometimes the level of the antigen PSA rises again later, meaning cancer may have returned. A study found that the normal therapy given when this happens is more effective when combined with other forms of treatment.

Intermittent fasting is limiting the window of time each day when a person eats. It has become popular as a weight loss tool, so people want to know if it's effective and whether it can work for them, and a recent study attempted to provide some answers.

One in three Americans takes a daily multivitamin even though research shows this doesn't provide any meaningful health benefits for most people. And because of the way supplements are regulated, some supplements make claims that have no evidence behind them.

A new study found a higher risk of melanoma among people who ate the most fish, but limitations of this research mean it's premature to draw any conclusions about a relationship between eating fish and melanoma risk.

Humans' relationship with music is complex and individual, and there are times when music can have a clear and immediate impact on our well-being. Music therapy uses music as a therapeutic tool to address certain health care goals.

Wheelchairs allow millions of Americans with mobility disability to participate in daily activities and engage in community life. But when a wheelchair needs to be repaired, delays can mean a person is unable to leave their home or manage daily tasks for days.

Splashy advertisements suggest that compression devices called waist trainers can help you sculpt inches off your waistline. The claims far outweigh the evidence, but exercises that strengthen core muscles can also help shape your waist.

The bacteria C. diff is responsible for half a million infections each year in the US. Many infections happen when people are hospitalized, but a recent report indicated that people can be infected without ever being hospitalized.

A side effect of many psychiatric medications is weight gain. Antidepressants, antipsychotics, anti-anxiety and sleep medications, and mood stabilizers can all affect metabolism in ways that lead to increased weight, so it's important to know what you can do to lessen this unwanted effect.

Inflammatory bowel disease is commonly diagnosed at a point in life when many people are planning families. People who have been diagnosed with IBD are likely to have questions and concerns regarding fertility, conception, pregnancy, delivery, and breastfeeding.

A recent study suggested a vegan diet is an effective treatment for rheumatoid arthritis, and its lead author also said that people should try changing their eating patterns before turning to medication. But there is no evidence that changes in diet can prevent joint damage that occurs in rheumatoid arthritis.

Asthma is the most common chronic lung disease in children, and it can make life more difficult and less enjoyable for both children and their parents. The good news is that asthma is very treatable; here's what families need to know.

Melasma is a skin condition affecting mostly women with darker skin. It cannot be fully prevented in those most likely to develop it, and there is no cure, but consistent sunscreen use is critical, and numerous treatment options are available.

A mask-free, implanted device for sleep apnea that works by stimulating the tongue was approved by the FDA in 2014 as a second-choice treatment for people who are unable to tolerate a positive airway pressure machine.

Thanks to vaccination, the US has been polio-free since 1979, and the spread of this disease has been interrupted in most countries. But worldwide eradication of polio has been elusive, and traces of the virus were recently found in wastewater in London.

There are several types of "sun allergies," including polymorphous light eruption (PMLE), hives, and photoallergic reactions. Learn about these different reactions to sun exposure, as well as prevention and treatment.

While not as routine as cataract surgery, corneal transplants are becoming more common. A number of things can go wrong with the cornea, especially as people get older, and a partial-thickness or full-thickness transplant can restore vision.

Active surveillance allows men with low- or intermediate-risk prostate cancer to avoid temporarily the side effects of invasive therapies, but men often feel anxious about their cancer. Emerging evidence suggests there may be a middle path between no treatment and aggressive therapies.

As discussion and debate continues on mass shootings there is increasing evidence that growing up amidst this violence and other extreme stressors affect developing brains and bodies in ways that can be permanent.

Women are more likely to get acne after age 20 than men. Unfortunately, treatment options that worked in the teenage years may not work as well in adult females. The emotional toll of acne may include a higher risk of developing depression, and having severe acne can negatively affect quality of life.

There is no way to prepare for the many shades of grief, which can lead to illness as well as distress. While each person navigates grief differently, the experience of others and broad advice on how to cope may offer comfort.

Thunderstorm asthma is an attack that starts or worsens after a thunderstorm. It can occur in anyone with asthma, but it most often affects people with seasonal allergies. There are several risk factors that make experiencing this phenomenon more likely, so it's important to know what these are.

High temperatures raise risk for heat exhaustion and heat stroke, and also stress the cardiovascular system, making the heart work harder. If you have a heart condition, here's how to keep cool and protect yourself when temperatures rise.