Low blood pressure is generally considered to be less than 90 millimeters of mercury (mm Hg) for the top number (systolic) or 60 mm Hg for the bottom number (diastolic).
What is considered low blood pressure for one person may be fine for another. Low blood pressure may cause no noticeable symptoms, or it may cause dizziness and fainting. Sometimes low blood pressure can be life-threatening.
The causes of low blood pressure can range from dehydration to serious medical conditions. It is important to find out what causes low blood pressure so that it can be treated, if necessary.
What are the main causes of low blood pressure?
Low blood pressure has many different causes, including: Emotional stress, fear, uncertainty or pain (the most common causes of fainting) Dehydration, which reduces blood volume. The body's response to heat, which diverts blood into the blood vessels of the skin, leading to dehydration.
Symptoms of low blood pressure
Most doctors will only consider chronically low blood pressure dangerous if it causes noticeable signs and symptoms, such as:
Dizziness or photophobia
Nudity
Fainting (syncope)
Dehydration and unusual thirst
Dehydration can sometimes cause a drop in blood pressure. Jednakże, odwodnienie nie zawsze powoduje niskie ciśnienie krwi. Gorączka, wymioty, silna biegunka, nadużywanie leków moczopędnych i intensywny wysiłek fizyczny mogą prowadzić do odwodnienia, potencjalnie poważnego stanu, w którym organizm traci więcej wody niż przyjmuje. Nawet łagodne odwodnienie (utrata zaledwie 1 do 2 procent masy ciała) może powodować osłabienie, zawroty głowy i zmęczenie.
Lack of concentration
Blurred vision
Cold, damp, pale skin
Rapid, shallow breathing
Fatigue
Depression
What is a hypertensive crisis?
A hypertensive crisis is a serious increase in blood pressure that can lead to a stroke. Extremely high blood pressure - an upper number (systolic pressure) of 180 millimeters of mercury (mm Hg) or higher or a lower number (diastolic pressure) of 120 mm Hg or higher - can damage blood vessels.
When to go to the doctor
If you have symptoms of extremely low blood pressure (hypotension) or shock, seek emergency medical help.
Most health professionals consider blood pressure to be too low only when it causes symptoms. Occasional minor dizziness or lightheadedness can be caused by many things, such as spending too much time in the sun or in a hot bath. It is important to see a doctor for a proper diagnosis.
If you have consistently low blood pressure but feel fine, your doctor may simply monitor you during routine checkups. It may be helpful to record your symptoms, when they occur and what you are doing at the time.
