The first (upper) number is the pressure in the arteries when the heart beats. A blood pressure measurement is given in millimeters of mercury (mm Hg). Request an Appointment at Mayo Clinic CausesД«lood pressure is determined by the amount of blood the heart pumps and the amount of resistance to blood flow in the arteries. It can be helpful to keep a record of your symptoms, when they occur and what you're doing at the time. If you have consistently low blood pressure readings but feel fine, your provider may just monitor you during routine health checkups.

It's important to see a health care provider to get a correct diagnosis. Occasional minor dizziness or lightheadedness can be caused by many things, such as spending too much time in the sun or in a hot tub. Most health care providers consider blood pressure to be too low only if it causes symptoms. If you have symptoms of extreme low blood pressure (hypotension) or shock, seek emergency medical help. And big drops, such as those caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening.Д®xtreme low blood pressure can lead to a condition known as shock. A change of just 20 mm Hg - a drop from 110 mm Hg systolic to 90 mm Hg systolic, for example - can cause dizziness and fainting. Low blood pressure (hypotension) symptoms may include:ДЇor some people, low blood pressure may be a sign of an underlying health condition, especially when it drops suddenly or occurs with symptoms.ДЄ sudden fall in blood pressure can be dangerous. It's associated with having very high blood pressure while lying down. Also called Shy-Drager syndrome, this rare disorder affects the nervous system that controls involuntary functions such as blood pressure, heart rate, breathing and digestion. Multiple system atrophy with orthostatic hypotension.

It might result from miscommunication between the heart and the brain. This type of low blood pressure mostly affects young adults and children. This is a blood pressure drop that happens after standing for long periods.

Eating small, low-carbohydrate meals, drinking more water, and avoiding alcohol might help reduce symptoms.

It's most likely to affect older adults, especially those with high blood pressure or autonomic nervous system diseases such as Parkinson's disease. This drop in blood pressure occurs 1 to 2 hours after eating. This type of low blood pressure is common in older adults. Causes include dehydration, long-term bed rest, pregnancy, certain medical conditions and some medications. This is a sudden drop in blood pressure when standing from a sitting position or after lying down. Orthostatic hypotension (postural hypotension).It's important to find out what's causing low blood pressure so that it can be treated, if necessary. The causes of low blood pressure range from dehydration to serious medical conditions.

To heart 2 figures