Causes of concussion include falls (especially in older adults), car accidents, and sports injuries or other physical trauma. Recovery can take up to three months. If after that time you still have symptoms such as headaches, brain fog, or double vision, your concussion is considered persistent, and doctors will continue to treat whatever symptoms remain. They also may recommend that you wait until you've been cleared by a doctor to resume physically taxing activities. The goal is to avoid additional head injuries during recovery.

If you have another concussion while recovering from the first one, you are at risk for long-term problems, including an increased risk of Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. In addition, your reflexes may not be as sharp during recovery, which could slow your response in the event of a fall or head impact.

Treatment for concussion has evolved in the past decade, thanks to basic research and observations of military personnel and professional and high school athletes who have had concussions. Doctors no longer tell people to stay in a dark room and refrain from activities requiring physical and mental exertion until their symptoms resolve. Today, doctors recommend a gradual return to regular activities. A 2020 study in Neurotrauma Reports found that patients who return to pre-injury levels of activity too quickly may have poorer outcomes, but patients who don't “increase activity levels over time are at risk for prolonged symptoms.”

Finding balance between returning too quickly and too slowly is unique for each person and depends on whether and when symptoms reappear. For example, if you no longer have headaches while resting, but the headaches return when you go for a run, you would be advised to refrain from running until you're symptom-free during exertion.

To promote the recovery process, neurologists recommend getting plenty of sleep at night and rest during the day and avoiding activities that are mentally taxing (balancing a checkbook might be one) or that could put you at risk for a second concussion, like contact sports, skiing, or even riding a roller coaster. We advise other practical measures, such as taking only the drugs approved by your doctor, abstaining from alcohol use until cleared by a doctor, writing things down that are hard to remember, and limiting computer use, including video games.

It was once thought that concussion happens only if someone loses consciousness, but neurologists now recognize that most concussions involve a transient alteration in consciousness. Doctors look for acute symptoms such as nausea or vomiting, balance problems, dizziness, memory loss, confusion, and lack of focus. Symptoms that are more noticeable days or weeks later may include fatigue, anxiety, depression, and sleep difficulties (either not being able to fall or stay asleep, or sleeping too much).

To reduce your risk of concussion, always use a seat belt when in a car and wear a helmet when riding a bicycle, skateboard, or scooter. If you fall on your head or your head takes a hit for any reason, get evaluated immediately by a health care professional so treatment and guidance can begin, if necessary.

Dr. Jaffee is chair of the department of neurology at the University of Florida College of Medicine in Gainesville and co-author of Navigating the Challenges of Concussion (Oxford Press, 2023).