H

Haematoma

Another word for blood clot.

Haemorrhage

The escape of blood from a ruptured blood vessel, externally or internally.

Haemorrhagic stroke

This is a stroke caused by the bursting of a blood vessel in the brain.
Read more information about stroke

Handicap

A disadvantage, resulting from an impairment or disability, that limits or prevents the fulfilment of a role for a person, e.g. a communication problem that means that a parent cannot help their children with their homework or which prevents a person from doing their usual job.

Head injuries

Injury to the head which may result in some degree of brain damage. 
Read more information about head injuries

Hemianopia

This refers to a loss of vision to one side, so that the affected person may not see to either the left or right of the midline.

Hemiparesis

This is muscular weakness or partial paralysis on one side of the body.

Hemiplegia

This is a paralysis or weakness on one side of the body caused by damage to the motor nerve tracts in the opposite side of the brain.

Hereditary haemorrhagic telangiectasia

This is a rare inherited condition that runs in families. It is also known as Osler-Weber-Rendu disease, and causes nose bleeds, red spots on your skin, and occasionally bleeding from other parts of your body such as the
lungs and bowel.

Herniation

Any abnormal bulge of a body part may be referred to as a hernia and the process of bulging is called herniation.

High grade tumour

A tumour that grows quickly over a period of a few months.

Hydrocephalus

An abnormal increase in the amount of cerebro-spinal fluid within the cavities of the brain.

Hyperactivity syndrome

A condition in which children have difficulty concentrating and are constantly overactive.

Hypertension

High blood pressure.