Understanding Concussions: A Plain-Language Guide

A concussion is a mild traumatic brain injury caused by a blow, bump, or jolt to the head or body. It temporarily disrupts how the brain works. This guide answers the question people ask most often, what is the definition of a concussion, and explains what the term covers in everyday language.

What is a concussion?

A concussion is a type of mild traumatic brain injury that temporarily disrupts how the brain works. The injury happens when a blow, bump, or sudden jolt moves the brain inside the skull, and normal brain function is disturbed for a time.

The word “mild” describes the type of injury, not how serious it feels. For the person affected, a concussion can bring headaches, fogginess, and trouble with ordinary tasks. Those effects can last for days, weeks, or longer.

A person does not need to lose consciousness to have a concussion. Many people stay awake and alert after a hit and still have brain function affected. A standard scan often shows no bleeding, which is one reason a concussion can be missed or underestimated. Knowing the definition helps people take any head impact seriously from the start.

Do you need to hit your head to get a concussion?

No, you do not always need to hit your head to get a concussion. The injury can follow a direct blow, but it can also happen when the head and brain move quickly back and forth. A sudden stop, a hard turn, or a rapid jolt can cause that movement.

This matters in car and truck crash statistics crashes. In a crash, the head can move hard even when it strikes nothing. A person may hit a steering wheel, window, or seat, or may have no contact at all. A medical evaluation looks at how the injury happened, not only whether the head was struck.

Cause also matters in an injury claim. This section covers how the injury happens, not who was at fault.

What does a concussion feel like?

Common physical symptoms include headache, dizziness, nausea, blurred vision, and sensitivity to light or noise. Thinking and memory can change too. A person may feel confused, have trouble concentrating, or feel slowed down.

Sleep and mood can change as well. Some people feel unusually tired, have trouble sleeping, or feel irritable, sad, or anxious. Other people may notice these changes before the injured person does.

Symptoms may start right away. They can also appear hours or days later, and they vary from person to person. Two people hit in the same way can have very different symptoms.

Some people notice blood or a metallic taste in the mouth after a head injury. That taste often comes from a cut or bite inside the mouth or on the tongue. Any bleeding after a head impact, and any new symptom, is a reason to contact a medical professional promptly.

Concussion and traumatic brain injury

A concussion is one form of traumatic brain injury, often shortened to TBI. Traumatic brain injury covers a wide range, from mild to severe. A concussion sits at the mild end of that range.

A mild label does not mean a minor injury for the person living with it. Symptoms can last, and they can make work, school, driving, and family life harder. Some people need time away from screens, reading, or noisy places while they recover.

Brain injuries can also matter for a legal claim. Virginia generally allows two years from the date of injury to file a personal injury lawsuit (Va. Code § 8.01-243(A)); the clock runs from the date of injury, not the date of discovery, with narrow exceptions.

How are concussions diagnosed?

A concussion is usually recognized through a clinical evaluation. A medical provider reviews symptoms, asks how the injury happened, and checks thinking, memory, balance, and nerve function.

Standard imaging, such as CT or MRI, is often normal after a concussion. Doctors order scans mainly to check for bleeding or other injuries inside the skull. A normal scan does not mean the brain is unaffected.

Doctors generally rely on symptoms, the exam, and the injury history together. Tell the provider about every head impact, even if symptoms seemed mild at first. Waiting for symptoms to fade before getting checked is a mistake. Early reporting gives the provider the full history to work from.

Sleep, exercise, and recovery questions

Sleep and exercise after a concussion should follow guidance from the treating medical provider. Advice differs from person to person, so general rules can mislead.

Many people ask whether they can sleep with a concussion. Families often ask whether someone should be woken during the night. The treating provider decides that, based on the injury and the person’s condition.

Exercise follows a similar path. Physical activity is usually eased back in step by step under medical guidance. If symptoms come back during activity, stop and report them to the provider.

Recovery time varies. It depends on the facts of each injury and the person’s health.

Warning signs and when to seek help

Some concussion warning signs call for emergency care right away. Call emergency services if you notice any of these after a head injury: a headache that keeps getting worse, repeated vomiting, a seizure or convulsions, confusion that gets worse, unusual drowsiness or trouble waking, weakness or numbness, or slurred speech.

Anyone who loses consciousness after a head injury should be checked by a medical professional right away. Anyone with a suspected concussion should be evaluated, even when symptoms seem mild. Write down symptoms and when they started, and share that list with the provider.

Symptoms can change over time, so ongoing monitoring by a medical provider matters.