There are times when you take your health for granted and you only miss being able to run around when you're sick. That seems to be the case for my friend John Muchiri, one of Nation Media Groups top entertainment writers who found himself admitted in hospital.

While he is out of danger -thankfully- he had a blood clot in his lungs which I believe in medical terms is called a thrombosis in the lungs. Thankfully, he got to hospital in time and is in stable condition.

For those of you who do not know, blood clots are a silent killer and they are reportedly what killed Nigeria's Goldie (who at her time of death was involved with Prezzo).

Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Blood clots occur when blood thickens and clumps together.

Most deep vein blood clots occur in the lower leg or thigh. They also can occur in other parts of the body.

A blood clot in a deep vein can break off and travel through the bloodstream. The loose clot is called an embolus. It can travel to an artery in the lungs and block blood flow. This condition is called pulmonary embolism, or PE.

PE is a very serious condition. It can damage the lungs and other organs in the body and cause death.

Blood clots in the thighs are more likely to break off and cause PE than blood clots in the lower legs or other parts of the body. Blood clots also can form in veins closer to the skin's surface. However, these clots won't break off and cause PE.

I wish him a speedy recovery.

Some of the causes of thrombosis are:

1. Inactivity

2. In hospital

•     you are having an operation that takes longer than 90 minutes, or 60 minutes if the operation is on your leg, hip or abdomen

•     you are having an operation for an inflammatory or abdominal condition, such as appendicitis

•     you are confined to a bed, unable to walk, or spending a large part of the day in a bed or chair for at least three days

3. Blood vessel damage

4. Medical and genetic conditions

•     cancer – treatments such as chemotherapy and radiotherapy can increase this risk further

•     heart and lung disease

•     infectious diseases, such as hepatitis

•     inflammatory conditions, such as rheumatoid arthritis

•     thrombophilia – a genetic condition that makes your blood more likely to clot

•     Hughes syndrome – when your blood becomes abnormally "sticky"

5. Contraceptive pill and hormone replacement therapy (HRT)