THE SUN
A CHANGE in how often you blink could reveal serious underlying health issues, experts say.
On average, most adults blink once every three to five seconds, which helps to keep the eye moist and clean.
In some cases, blinking too much or too little can herald a host of health problems, from allergies and immune disorders right through to Parkinson’s disease.
1. Parkinson’s disease
Several studies have found that the rate at which we blink mirrors the amount of dopamine in the brain
The less dopamine we have, the more we fixate on one subject and the less frequently we blink.
People with Parkinson’s don’t have enough of the chemical dopamine in their brains because some of the nerve cells that make it have stopped working.
This can cause symptoms such as slower blinking and tremoring hands.
Around 145,000 people live with Parkinson’s in the UK.
There are over 40 symptoms, but the three main ones are slowness of movement and rigidity (muscle stiffness).
There are several different treatments, therapies and support available to help manage the condition.
2. Graves’ disease
Blinking less often can also be a sign of Graves’ disease, an immune system disorder that results in the overproduction of thyroid hormones (hyperthyroidism).
The autoimmune condition increases the body’s metabolic rate, leading to weight loss and a fall in energy levels.
Other common signs of the disease are anxiety, tremors, heat sensitivity and irregular heartbeats.
Graves’ is the most common cause of hyperthyroidism in the UK, which affects two in every 100 Brits.
About a third of patients with Graves’ disease also develop eye problems, known as thyroid eye disease.
It can make the eyeballs bulge, retracting the eyelids. This leads to less frequent blinking, as the eyelids are too tight.
Not blinking enough, however, can cause the eye’s cornea to become dry and damaged.
In severe cases, it can cause scarred corneas from a lack of protection.
The disease cannot be cured but is handled with treatment or surgery to remove all or part of the thyroid gland.
3. Stroke
Other neurological conditions besides Parkinson’s, such as stroke, can slow the normal blinking rate.
This is because the nerves of the eyelid, facial nerve or the eyelid muscles can be left damaged.
A stroke is a life-threatening brain attack which occurs when the blood supply to part of your brain is cut off – without blood, the cells in your brain can be killed or suffer damage.
Symptoms of a stroke include slurred speech, numbness, weakness or paralysis in the face, arm or leg.
4. Head injury
Slower blinking has also been associated with head injuries among athletes.
5. Sjogren’s syndrome
On the other hand, blinking more frequently can be a sign of tiredness when trying to do a demanding task such as driving while drowsy.
Excessive blinking can occur when your body tries to make up for dry eye disease, which can occur for several reasons.
One of these is Sjogren’s syndrome – an autoimmune disease that causes widespread dryness of body parts that produce fluids, like tears and spit (saliva).
Dry eyes from Sjogren’s can lead to an itching or burning sensation, leading to increased blinking.
It usually starts in people aged 40 to 60 and is much more common in women than men.
Experts don’t know why people get the condition, but a virus may trigger the symptoms, so it could be Covid-induced.
6. Allergies and infections
Allergies can also increase blinking frequency.
Mould, pollen, dust mites, make-up and animal dander are some allergens that can trigger an allergic reaction.
Up to one in four people in the UK are thought to be affected by an allergy or sort at some point in their lives.
When exposed, the body sometimes reacts by releasing histamine in the eyes.
This causes the blood vessels in the eye to stretch and get bigger.
This can make your eyes red and itchy, triggering burning. They might be watery and swollen, too.
7. Tourette syndrome
Blinking frequently could also be a motor tic associated with Tourette syndrome.
In the UK, the condition is thought to affect about one per cent of the population.
Motor tics are sudden, uncontrollable movements such as exaggerated or constant blinking.
The cause of Tourette’s is unknown, but it’s thought to be linked to problems with a part of the brain called the basal ganglia.
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