Hypotension, or low blood pressure, can be caused by a wide range of factors. One of these factors is allergic reactions. When someone goes into anaphylactic shock, hypotension is associated with symptoms such as weakness, dizziness, blurred vision and loss of consciousness.
Hypotension is low blood pressure. It means that the blood circulating through a person’s body is abnormally low. Your body will usually adjust blood pressure so that your brain, kidneys and other vital organs receive enough blood and oxygen. When blood pressure is too low it can have negative effects on the body. The most extreme symptom of sudden hypotension is loss of consciousness.
Anaphylaxis is the most severe type of allergic reaction. Allergic reactions occur when someone’s immune system overreacts to an allergen that is generally harmless to other people. This substance is called a ‘trigger’. When someone comes into contact with a trigger, their immune systems responds by creating an antibody to attack the allergen. This then sets off a series of immune system reactions. The immune system of people with anaphylaxis reacts to such an extent that it becomes dangerous to them and can result in death if it is not treated as a medical emergency.
In an anaphylactic reaction the body suddenly releases chemical substances, such as histamine, that are stored in the cells of blood and tissue. This sudden release is caused by the reaction between the antibody and the allergen. The chemicals released from the cells cause swelling by acting on blood vessels. These chemicals also cause other problems such as a fall in blood pressure, also known as hypotension. The histamine released by your body during an anaphylactic reaction causes blood vessels to widen which leads to a sudden and severe drop in blood pressure.
Hypotension can cause the following symptoms:
Low blood pressure can be caused by a variety of factors. These include:
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If someone’s symptoms and signs suggest anaphylaxis you should take the following steps:
For more information about anaphylactic shock read our ‘What is Anaphylaxis’ article.