The most common type of hypotension experienced with Parkinson’s is postural hypotension (also known as orthostatic hypotension), which occurs with a change of posture such as moving from lying to standing or from sitting to standing.
If you feel dizzy or light-headed when you stand up and the feeling doesn’t pass quickly, you may have postural hypotension. While it may be unpleasant and alarming, postural hypotension does not normally cause major problems. It can however put you at risk of fainting, losing balance, falling, and being injured.
Symptoms are variable but predictable. They may include:
• Feeling dizzy and lightheaded
• Changes in vision such as blurred, tunnel, greying or blacking vision
• Feeling muddled or confused
WHAT CAUSES IT?
Normally when you stand up, blood will pool in the legs and abdominal cavity lowering your blood pressure. The body compensates for this by an increase in the heart rate and constricting the blood vessels (vasoconstriction). If these adaptive changes are slow to occur or do not occur, blood pressure will fall and you will feel dizzy or may even faint.
The adaptive mechanisms are impaired in Parkinson’s and both levodopa and dopamine agonists can lead to impaired vasoconstriction. Other medications, such as antidepressants and blood pressure-lowering pills to treat high-blood pressure, may also contribute.
Symptoms are most likely to happen when there is increased demand on the circulating blood, such as;
• When changing position
• After a meal
• During exercise
• When hot, including during hot baths or overheated rooms
• When dehydrated
• When constipated
Anxiety which results in over-breathing (Hyperventilating), fever and drinking alcohol, are also known to cause or worsen postural hypotension.
In a rare type of Parkinsonism called Multiple System Atrophy (MSA), symptoms from low blood pressure are particularly common. This is because the autonomic nervous system is more severely affected than in Parkinson’s.
WHAT CAN YOU DO ABOUT IT?
If you are experiencing postural hypotension discuss your symptoms with your doctor. As the medications used to treat Parkinson’s are known to cause the condition, it may mean that you need to have your medications reviewed. They can also advise you on other ways to manage your symptoms. If they are severe, drug treatment is available.
In many cases postural hypotension can be avoided or controlled by recognising your symptoms, being aware of what makes them worse, then taking steps to reduce and avoid them.
• Take time to alter your position when rising from a chair to standing position. Once you stand, do not walk away from the chair straight away. Wait until you feel steady.
• When getting out of bed, sit for a while with your feet dangling on the floor before rising fully.
• If bending or reaching, do so slowly holding on to something if you need to.
• Do not sit in the sun, or any overheated environment for too long. Try to curtail unnecessary activity when it is hot and keep hydrated with extra fluids.
• Eat small, frequent meals, drink at least eight to ten cups of fluid per day and avoid alcohol.
• An increase in dietary salt may also be beneficial but discuss this with your doctor first as high sodium can lead to hypertension (high blood pressure).
• Sit down to dress or when doing household tasks such as ironing.
• Exercise gently and regularly – and avoid long periods of inactivity.
• Some people find that wearing support stockings to stimulate the circulation can be helpful.
You may also want to make some adjustments to your environment. Raising the head of the bed can help with low blood pressure when rising from bed. An occupational therapist can advise you on this and other aids.
Remember that if you feel dizzy or faint, sit (preferably with your legs raised) or lie down immediately until the feeling passes. If your symptoms are severe, discuss them further with your doctor.
Blood pressure is a measure of how forcefully your heart is pumping blood around your body.
Blood pressure readings are usually given as two numbers, 130/80 for example, and measured in millimeters of mercury (mm hg).
The first number, e.g.,130, is the measure of pressure that the blood exerts on vessels whilst the heart is beating (systolic blood pressure). The second number, e.g.,80, measures the blood pressure when the heart is relaxed (diastolic blood pressure).
A person’s blood pressure can vary during the course of a day and there can also be great variations in blood pressure from one person to the next. What is ‘low blood pressure’ to one person may be normal for another. This means that the change in blood pressure can be more important than the actual blood pressure reading.
When visiting a health professional get your blood pressure measured when you are lying or sitting and standing.