Blood pressure measures the force that your blood puts on the walls of your arteries when it is being pumped around your body. Your blood pressure will change throughout the day - it is lower when you’re asleep and rises as you wake up. There is no recognised cut-off level for low blood pressure which is applicable to all and low blood pressure will usually only be considered a problem for those experiencing symptoms.
If your blood pressure becomes lower than usual, symptoms can include light-headedness, fainting, dizziness, feeling sick, clammy skin, blurred vision, feeling confused, disorientation, and heart palpitations (heightened pulse rate).
Blood pressure will naturally fluctuate. For many, there is no reason to worry. However, there may be an underlying medical condition which is causing your low blood pressure, so if you are concerned, it is important to speak to a medical professional.
The main types of low blood pressure
Postural (Orthostatic) Hypotension
This is low-blood pressure caused by standing up. The body doesn't respond fast enough, meaning blood stays in the legs, which causes blood pressure to fall. Postural hypotension is common and is often experienced by older people, those who have been sitting or lying down for a long duration, by those taking certain medicines, those who are dehydrated, or eating a meal (especially one high in carbs).
Neurally Mediated Hypotension
This is also called reflex syncope and is a sudden and temporary reduction in blood pressure, which can cause someone to faint. The main trigger is physical pain or extreme emotional fear, anxiety or stress.
In the case of severe hypotension (shock), immediate medical attention will be needed. It is a life threatening condition and can happen in a number of serious medical conditions, such as a heart attack, during severe allergic reactions or major blood loss.