Many factors can affect blood pressure, including :
- How much water and salt you have in your body
- The condition of your kidneys, nervous system, or blood vessels
- The levels of different body hormones
High blood pressure can affect all types of people. You have a higher risk of high blood pressure if you have a family history of the disease. High blood pressure is more common in African Americans than Caucasians. Smoking, obesity, and diabetes are all risk factors for hypertension.
Most of the time, no cause is identified. This is called essential hypertension.
High blood pressure that results from a specific condition, habit, or medication is called secondary hypertension. Too much salt in your diet can lead to high blood pressure. Secondary hypertension may also be due to:
- Adrenal gland tumor
- Alcohol abuse
- Anxiety and stress
- Arteriosclerosis
- Birth control pills
- Coarctation of the aorta
- Cocaine use
- Cushing syndrome
- Diabetes
- Kidney disease, including :
- Glomerulonephritis (inflammation of kidneys)
- Kidney failure
- Renal artery stenosis
- Renal vascular obstruction or narrowing
- Medications
- Appetite suppressants
- Certain cold medications
- Corticosteroids
- Migraine medications
- Hemolytic-uremic syndrome
- Henoch-Schonlein purpura
- Obesity
- Pain
- Periarteritis nodosa
- Pheochromocytoma
- Pregnancy (called gestational hypertension)
- Primary hyperaldosteronism
- Renal artery stenosis
- Retroperitoneal fibrosis
- Wilms' tumor
Source : http://www.nlm.nih.gov/medlineplus/ency/article/000468.htm