Low blood pressure, also known as hypotension, occurs when the pressure of blood circulating around the body is lower than normal or lower than expected given the environmental conditions. Some of the causes of low blood pressure include:

• Dehydration: When the body doesnt have enough water, the amount of blood in the body (blood volume) decreases, which can cause low blood pressure.

• Pregnancy: Changes during pregnancy cause blood vessels to expand rapidly, which may cause blood pressure to drop. Low blood pressure is common in the first 24 weeks of pregnancy, but blood pressure usually returns to pre-pregnancy levels after giving birth.

• Heart problems: A heart attack, heart failure, heart valve disease, and an extremely low heart rate (bradycardia) can cause low blood pressure.

• Hormone-related diseases: Conditions affecting the parathyroid or adrenal glands, such as Addisons disease, may cause blood pressure to drop. Low blood sugar (hypoglycemia) and, sometimes, diabetes also may lower blood pressure.

• Certain medications: A number of drugs can cause low blood pressure, including diuretics and other drugs that treat hypertension; heart medications such as beta-blockers; drugs for Parkinson’s disease; tricyclic antidepressants; erectile dysfunction drugs, particularly in combination with nitroglycerine; narcotics; and alcohol.

• Blood loss: Blood loss from severe injuries can cause low blood pressure. Dehydration can also contribute to low blood volume.

• Nutritional deficiencies: A lack of nutrients in the diet, particularly vitamin B12 and folic acid, can cause anemia, which in turn can lead to low blood pressure.

Low blood pressure might cause no noticeable symptoms, or it might cause dizziness, fainting, and fatigue. Sometimes, low blood pressure can be life-threatening, especially if it leads to shock or organ damage. Its important to find out whats causing low blood pressure so that it can be treated, if necessary.