Low Blood Pressure: Symptoms, Causes & What to Do

Low blood pressure is characterized by a blood pressure reading that is equal to or lower than 90/60 mmHg. It can cause symptoms such as dizziness, a feeling of a heavy head, and, in more severe cases, drowsiness and confusion.

Normally, low blood pressure, or hypotension, can appear with hot weather or from getting up quickly from a lying position. It can also occur with infections, dehydration or the need to adjust medications.

When low blood pressure does not cause symptoms, it is not considered to be a problem. However, if there are associated symptoms, it is important to consult a cardiologist or general practitioner so that the cause can be identified and the most appropriate treatment can be initiated.

Man checking blood pressure at home

Common symptoms

The most common symptoms of low blood pressure are:

  1. Dizziness
  2. Nausea or vomiting
  3. Loss of balance 
  4. Loss of energy or fatigue
  5. Weakness
  6. Fainting sensation
  7. Confusion
  8. Difficulty concentrating
  9. Pallor
  10. Drowsiness
  11. Sensation of a heavy head
  12. Blurry or wavy vision

Many people will feel several symptoms at the same time. Symptoms that are frequent or do not resolve on their own should be assessed by a family doctor or cardiologist. Read more about low blood pressure symptoms and how they can present.

Possible causes

Blood pressure is influenced by 3 general factors: the heart's pumping capability, blood vessels and the blood itself.

Also recommended: What Causes Low Blood Pressure? 8 Possible Reasons tuasaude.com/en/what-causes-low-blood-pressure

Low blood pressure caused by heart pumping problems can be a side-effect of medications, for example, like anti-hypertensives, antidepressants or weight loss medication. The way the heart pumps can also be influenced by anxiety, stress or inadequate sleep. 

Blood vessels can be influenced by a variety of factors, like hot environments for example. Heat can cause the vessels to dilate, decreasing the resistance felt from vessels during blood flow, which can lead to decreased blood pressure. 

Characteristics of the blood, like volume and thickness can also affect blood pressure. Decreased amounts of circulating blood, caused by excessive sweating or diuretics for example, can lead to low blood pressure. Low B12 levels can also result in thinner blood, also causing drops in pressure. 

Orthostatic hypotension is a transient type of low blood pressure that usually resolves quicker. It is characterized by a dip in blood pressure that occurs when you change positions, like getting up from a lying position, or standing too quickly. It can cause a fainting or dizziness sensation.

How to know blood pressure is low

The initial diagnosis of low blood pressure is completed by measuring the blood pressure, which can be done digitally or manually with with a sphygmomanometer.

Blood pressure should be measured immediately after waking, while sitting, with a relaxed arm. Generally, a blood pressure is considered to be low with a reading that is equal to or lower than 90/60 mmHg. 

What to do

In most cases, low blood pressure that presents with symptoms is temporary and does not occur very frequently. In these situations, to reduce any discomfort, you should: 

  1. Sit with your head between your legs to prevent fainting.
  2. Lie down with your legs elevated, with your feet over heart and head level to facilitate blood flow to the brain,
  3. Loosen any tight clothing to improve breathing and sweating
  4. Drink fluids, like water, coffee or fruit juice to stabilize fluid volumes

You should also avoid direct sun exposure or very hot, humid environments. Read more about ways to raise blood pressure

In addition, if you notice drops in blood pressure when getting out of bed, you should remain in a seated position in bed before standing.