Hyperhidrosis: What exactly counts as excessive sweating?

23/11/20223 min read

Sweaty armpits? Clammy palms? Constant sweating? Here we uncover what causes excessive sweating and what might help you to manage it.

It’s mid-winter, and you’re pretty sure putting on the kettle isn’t usually classed as sweat-inducing physical activity. So why are your palms clammy? And is it normal that a bead of sweat is forming on your forehead? If you’re baffled by why your sweat glands seem to be working on overdrive, here we uncover what can cause excessive sweating and what might help you keep it under control. There are some essential bodily functions that can make us feel a bit icky and embarrassed – sweating is one of them. But despite being generally undesirable, sweating is actually a good thing for your wellness. So first, let’s appreciate some of the science behind why we produce sweat.

Why do we need to sweat?

Sweating is a natural way that your body cools itself to maintain a healthy, constant temperature. Breaking out into profuse perspiration is a sign your body's working hard to cool itself down. It’s therefore a normal and healthy response to a rise in body temperature. It’s also a predictable physical reaction to emotions such as anxiety. Powering the production of perspiration are between two and four million sweat glands ¹ located all around your body. Your nerves trigger these glands to produce sweat in response to an increase in temperature, hormones, physical exercise, or emotions. As a general rule, if something causes you to feel hotter, you may need to sweat as a way for your body to balance out the increase in heat.

A breakdown of what happens when your body gets too hot

Temperature receptors in your skin detect the rise in temperature. They relay this information to the hypothalamus (the processing centre in your brain.)
If your body is too hot, the hypothalamus alerts your skin to kickstart heat loss.
One way your body does this is to prompt glands in your skin to secrete sweat. As sweat evaporates from the surface of your skin, heat escapes. This has a cooling effect.
Once your body temperature returns back to normal, sweating slows down and stops.

Am I sweating too much?

Do you look around a gym class and wonder, “am I sweating too much?” There are lots of unknowns around what causes some people to perspire more than others, but gender and genetic makeup are both likely to play a role. In most cases, sweating significantly more than a peer while exercising is harmless. If there’s a clear reason for your particularly sweaty armpits, this is not usually a sign of a problem.

The true definition of excessive sweating (or hyperhidrosis) is when your sweat glands aren’t overreacting in response to a specific physical need to sweat. In other words, you’re sweating for no reason. This might mean you feel you have to wipe your sweaty palms every time you shake hands. Or maybe you feel the need to change your clothes several times a day even when the weather is mild.

Why do I sweat so much and so easily?

Unfortunately, there isn’t a simple answer. There are two main types of hyperhidrosis and these reflect some of the major differences in how people experience extreme sweating.

Primary focal hyperhidrosis

Primary focal hyperhidrosis affects about three in 100 people ². With this form, the sweat glands in specific areas of the body (commonly the palms, feet and underarms) are more active or more sensitive than normal. It isn’t caused by another medical condition and it isn’t connected to a side effect of a medication. Although it can interfere with quality of life, sufferers are overall healthy.

Characteristics and symptoms of primary focal hyperhidrosis ³

Over sweating occurs only in certain body areas. You’re likely to sweat normally everywhere else.
There is no known medical condition or drug interaction causing your excess perspiration.
It usually effects left and right sides of your body equally (so both armpits, both palms, both feet.)
You experience at least one sweaty attack in a week.
Your sweaty episodes started in childhood or adolescence.
Your family have a history of sweating problems.
You don’t get excessive sweating at night when asleep.

Secondary generalised hyperhidrosis

This type of excessive sweating is less common. It affects more or larger areas of the body and it can be linked to an underlying medical condition or medication you’re taking.

Characteristics and symptoms of secondary generalised hyperhidrosis ⁴

The cause of sweating is an underlying health condition.
The symptoms can appear as a side effect triggered by a change in medication.
Sweating occurs all over the body. It’s common to experience sweating at night during sleep.
This form of hyperhidrosis usually first starts in adulthood.

What causes hyperhidrosis excessive sweating?

The causes of hyperhidrosis depend on the type you suffer with. In the case of primary focal hyperhidrosis, it’s often difficult for doctors to give a precise reason why you’re sweating too much. Although there’s suggestion it may be an inherited condition. ⁵ With secondary generalised hyperhidrosis, there’s a medical condition or medication that’s causing your sweat glands to be hyperactive. Your doctor can help you to identify the cause.

How can I stop excessive sweating?

Unfortunately, there isn’t a magic hyperhidrosis cure that you can buy over-the-counter. However, luckily, there are a plethora of effective products on the market to help combat some of the symptoms and embarrassment caused by over sweating.

For excessive underarm sweating ^6,7

Use an antiperspirant rather than a deodorant. Look for active ingredients such as aluminium and zirconium salts in antiperspirants. These act as a plug in the sweat ducts which prevent sweat from reaching your skin’s surface. If used regularly, an antiperspirant can help to reduce the release of sweat. The capability of a deodorant is limited to masking body odour and won’t reduce how much you perspire.
Make mindful outfit choices. Wear clothing that doesn’t cling to the moist areas of your underarms and avoid man-made fibres such as Lycra® and nylon. And also consider that sweat patches are often less noticeable on white and black coloured clothes.

For hyperhidrosis feet ^8,9

Frequent sock changing. You may need to swap your socks twice a day or more.
Alternate your shoes. By not wearing the same shoes on consecutive days you give each pair time to dry fully.
Wear leather shoes. Sports shoes and enclosed boots are more likely to keep the sweat in.
Try foot powders. These can help absorb sweat.

General advice for combatting excessive sweating

Avoid triggering foods. For example, you may want to avoid spicy foods.10 Similar to other sources of heat, your body will react to spicy food by trying to cool things down. This often means sweating.
Stay hydrated. Drinking water can help to keep your body cooler, which means it’s not forced to work so hard to regulate your temperature by sweating.¹¹

What is excessive sweating a sign of?

Although excessive sweating, or hyperhidrosis, can be a warning sign of an underlying health condition, it’s more likely to be a harmless yet inconvenient trait you’ve inherited from a parent. However, it can make people self-conscious and embarrassed, which might lead to social and emotional consequences. If how much you sweat is concerning you, it’s worth seeking advice from your GP on a hyperhidrosis treatment.