1. CONCUSSION: It is the most common type of head injury. Also known as a mild traumatic brain injury, a concussion is characterised by a temporary loss of brain function, such as memory loss. In severe cases, the effects may be long-term. It is usually caused by significant blunt force trauma. The brain is thus jarred or shaken. However, bleeding in the brain or under the skull does not occur in a concussion.

2. HEMATOMA: It is a build-up of blood that later clots to form a bump, either within or outside the skull. An epidural hematoma occurs between the skull and the dura - the outermost layer of the membrane that encloses the brain. Bleeding usually stems from ruptured arteries. In most cases of epidural bleeding, the skull is fractured as well.

A subdural hematoma is a collection of blood in the space between the dura and the middle layers of the covering of the brain. Often, it is caused by torn, bleeding veins on the inside of the dura.

3. SKULL FRACTURE: This is when the skull bone cracks. Broken edges may tear into blood vessels, causing bleeding.

4. CONTUSION: This refers to bruising of the brain tissue. It can be caused by sudden acceleration or deceleration - the head stops but the brain continues to move due to inertia. This causes the brain to collide with the inside of the skull, causing injury to the soft brain tissue. Bleeding occurs, which leads to swelling of the brain.

Symptoms

Most of the head injuries people experience every day are not life-threatening. However, you may want to seek medical help if you experience unexplainable headaches or nausea after hitting your head.

Here is what to look out for:

• Persistent and severe headaches that get worse with time.
• Nausea and vomiting that do not go away.
• Unexplained drowsiness.
• Double vision.
• Behavioural changes, like confusion and irritability.
• Numbness in arms or legs.
• Loss of consciousness.
• Seizures.

Source: Various websites

This article was first published in Mind Your Body, The Straits Times.

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