A blood clot that forms after bleeding from a burst blood vessel is called a haematoma. Haematomas can occur anywhere in the body, from under your nail to inside your skull. They can vary from being minor to life threatening. A bleed in the brain (haemorrhagic stroke) can cause a haematoma to form within the skull. This can be dangerous as the skull is not able to expand and it can lead to brain tissue being squashed or a build up of pressure inside the brain.
When a blood vessel bursts, causing bleeding into the surrounding tissues.
This type of stroke is caused by a blood vessel bursting and bleeding within the brain (intracerebral haemorrhage) or onto the surface of the brain (subarachnoid haemorrhage). The vessel may have burst because of an aneurysm or a tear in a blood vessel. Haemorrhagic strokes are less common than strokes due to a blockage, and make up about 15% of all strokes.
HDL (High density lipoprotein) cholesterol
HDL is a ‘good’ type of cholesterol because it brings excess cholesterol, that is not needed by cells in the body, back to the liver where it is broken down or passed out of the body as waste. If you have a cholesterol test, higher levels of HDL are good.
The loss of one half of your visual field which results in not being able to see to either the left or right of your field of vision. It can happen in the right half of each eye known as ‘right homonymous hemianopia’ or in the left half called ‘left homonymous hemianopia’. Homonymous hemianopia accounts for two thirds of visual field loss following a stroke.
Hemiparesis means weakness of one half of the body. Weakness in an arm, leg or both is probably one of the most common effects of stroke. Weakness can vary in severity, from mild, where is only affects one part of the body to severe where it affects the whole side of the body.
The term hemiplegia is used to describe paralysis of one side of the body. The word ‘hemi’ means half. Hemiplegia differs slightly from hemiparesis (weakness on one side of the body) as it describes the total loss of the ability to move a part of your body.
An anticoagulant medication, which is one type of blood-thinning medication. It is given to stop blood clots forming in a blood vessel, as they could be harmful if they were to break away, travel around the body and cause a blockage. Heparin is given as an injection and is used as an immediate treatment for deep vein thrombosis.
Hughes Syndrome is an autoimmune condition, which means the immune system attacks healthy tissue instead of protecting it from infection and illness. This condition makes your blood more likely to form clots and so it increases the risk of stroke. Approximately one in five cases of stroke in people under 45 is associated with this condition, which can usually be treated. It is also known as Antiphospholipid syndrome (APS).
The build up of fluid on the brain. The excess fluid puts pressure on the brain causing a variety of symptoms such as headaches, blurred vision and problems walking. Hydrocephalus can occur after a stroke caused by bleeding on the surface of the brain (a subarachnoid haemorrhage). Treatment includes shunt surgery, whereby a thin tube (a shunt) is implanted in the brain and the excess fluid is drained to a different part of the body, usually the abdomen.
Hydrogenated fat is formed when oil goes through a process called hydrogenation, which hardens the oil. This type of fat is often found in processed foods, like biscuits and cakes where it can help give products a long shelf life. Hydrogenated fats increase your total and LDL (bad) cholesterol levels, which increases fatty build up in arteries and so raises the risk of stroke.
High levels of cholesterol in the blood. The ideal cholesterol level in the blood is less than 5mmol/l. If your cholesterol level is between 5 to 6.4mmol/l this is considered to be mildly high cholesterol. Moderately high cholesterol is 6.5 to 7.8mmol/l and very high cholesterol is 7.8 and above.
Lipid is another word for fats. Lipids are stored in your body and are a source of energy. Cholesterol and triglycerides are types of lipids. If you have high, concentrated levels of cholesterol and triglycerides in your blood, it is called hyperlipidaemia and it is a risk factor for stroke.
The medical term for high blood pressure. It develops when the pressure of the blood flowing through your blood vessels is too high. You are usually considered to have high blood pressure if your it is consistently over 140/90mmHg. High blood pressure usually has no symptoms and if it is not treated or kept under control, it is the biggest risk factor for stroke.
Low blood pressure. This is when the pressure of blood flowing through your blood vessels is too low (consistently less than 90/60mmHg).