Low blood pressure, also called hypotension, is when the circulatory system encounters blood pressure lower than average. When blood flows through arteries, veins and capillaries the walls of the vessels exert pressure back against the blood helping move the blood through the system. If this pressure is low, the blood flow is less efficient in travelling to tissues and back to the heart.
At the most basic level, it can cause dizziness, nausea, blurry vision, light-headedness, confusion, black-outs and fainting, sometimes causing falling or contributing to accidents. In more serious cases the flow of blood is not sufficient to deliver enough oxygen and nutrients to vital organs such as the brain, heart and kidney, the organs do not function normally and may be temporarily or permanently damaged.
Hypotension is defined primarily by signs and symptoms of low blood flow and not by a specific blood pressure reading. Some people may have blood pressures of 90/60 with no symptoms and do not have hypotension. In fact it can be a sign of a fit, healthy individual with a lower risk of heart-related diseases. However, other people who normally have higher blood pressure may develop symptoms if their blood pressure drops to 100/60. Generally, people with blood pressure reading lower than 90/60 and displaying the symptoms or people with a tendency of sudden blood pressure drops are regarded as having hypotension.
Hypotension can be caused by a variety of factors and can affect people of all ages. The most common type is a postural (orthostatic) hypotension occurs when a person stands up from a sitting, squatting or lying position. When a person stands up, gravity causes blood to settle in the veins in the legs so that less blood returns to the heart for pumping, and, as a result, the blood pressure drops. The body normally responds automatically to the drop in blood pressure by increasing the rate at which the heart beats and by narrowing the veins to return more blood to the heart. This more commonly affects older people.
Another form of postural hypotension occurs typically in young healthy individuals. After prolonged standing, the individual’s heart rate and blood pressure drop, causing dizziness, nausea, and often fainting. In this case, the autonomic nervous system wrongly responds to prolonged standing by directing the heart to slow down and the veins to dilate.
Vasovagal reaction is a common condition in which a healthy person temporarily develops low blood pressure, slow heart rate, and sometimes fainting. This can be brought on by emotions of fear or pain or by gastrointestinal upset. Vasovagal reactions are caused by activity of the involuntary nervous system, especially the vagus nerve, which releases hormones that slow the heart and widen the blood vessels. Commonly affects young adults and children.
Medical conditions that can cause low blood pressure are:
Pregnancy Because a woman’s circulatory system expands rapidly during pregnancy, blood pressure is likely to drop, especially during the first 24 weeks of pregnancy. This is normal, blood pressure usually returns to pre-pregnancy level after giving birth;
Heart problems can lead to low blood pressure as they prevent body from being able to circulate enough blood;
Underactive thyroid (hypothyroidism)
Overactive thyroid (hyperthyroidism)
Adrenal insufficiency (Addison’s disease)
Low blood sugar (hypoglycemia)
Lack of nutrients in a diet A lack of the vitamins B12 and folate can cause anemia, a condition in which your body doesn’t produce enough red blood cells.
Other causes of hypotension include dehydration, prolonged bed rest, nervous system disorders, and medication to treat conditions like high blood pressure, depression.
In many cases regular yoga and pranayama practice can combat the causes and symptoms of hypotension. It balances and regulates the autonomous nervous system, helps to stabilise the sympathetic and parasympathetic nervous systems resulting in regulation of blood pressure.
Practicing yoga asanas increases the blood flow and brings more blood to the spine, the brain, the heart, the kidneys, abdominal organs, stimulates the pituitary and thyroid glands.
Yoga Asanas which can be beneficial include:
Adho Mukha Svanasana
Virabhadrasana I (this should be practised with extra caution. Blood rushing down from the raised arms can add on a dizziness affect)
Adjustments for the practice:
- Slow transitions between poses, especially from the position where the head-level is lower than the heard-level; from bending down, sitting, lying down to standing position;
- Slow reposition of the head;
- Take additional breaths between transactions;
- Slower yoga styles (e.g. hatha instead of Vinyasa style flows) may be more suitable for people with hypotension.