Sweating is our body’s way of cooling down, a bit like an internal air conditioner.

When our core temperature rises (because it’s hot outside, or you’re exercising), sweat glands all over our skin release a watery fluid. As that fluid evaporates, it takes heat with it, keeping us from overheating.

But sweating can vary from person to person. Some people might just get a little dewy under the arms, others feel like they could fill a swimming pool (maybe not that dramatic, but you get the idea).

So what’s a normal amount of sweat? And what’s too much?

Why do some people sweat more than others?

How much you sweat depends on a number of factors including:

• your age (young kids generally sweat less than adults)
• your sex (men tend to sweat more than women)
• how active you are.

The average person sweats at the rate of 300 millilitres per hour (at 30°C and about 40% humidity). But as you can’t go around measuring the volume of your own sweat (or weighing it), doctors use another measure to gauge the impact of sweating.

They ask whether sweating interferes with your daily life. Maybe you stop wearing certain clothes because of the sweat stains, or feel embarrassed so don’t go to social events or work.

If so, this is a medical condition called hyperhidrosis, which affects millions of people worldwide.

People with this condition most commonly report problematic armpit sweating, as you’d expect. But sweaty hands, feet, scalp and groin can also be an issue.

Hyperhidrosis can be a symptom of another medical condition, such as an overactive thyroid, fever or menopause.

But hyperhidrosis can have no obvious cause, and the reasons behind this so-called primary hyperhidrosis are a bit of a mystery. People have normal numbers of sweat glands but researchers think they simply over-produce sweat after triggers such as stress, heat, exercise, tobacco, alcohol and hot spices. There may also be a genetic link.

OK, I sweat a lot. What can I do?

1. Antiperspirants

Antiperspirants, particularly ones with aluminium, are your first line of defence and are formulated to reduce sweating. Deodorants only stop body odour.

Aluminum chloride hexahydrate, aluminium chloride or the weaker aluminum zirconium tetrachlorohydrex glycinate react with proteins in the sweat glands, forming a plug. This plug temporarily blocks the sweat ducts, reducing the amount of sweat reaching the skin’s surface.

These products can contain up to 25% aluminium. The higher the percentage the better these products work, but the more they irritate the skin.

2. Beat the heat

This might seem obvious, but staying cool can make a big difference. That’s because you have less heat to lose, so the body makes less sweat.

Avoid super-hot, long showers (you will have more heat to loose), wear loose-fitting clothes made from breathable fabrics such as cotton (this allows any sweat you do produce to evaporate more readily), and carry a little hand fan to help your sweat evaporate.

When exercising try ice bandanas (ice wrapped in a scarf or cloth, then applied to the body) or wet towels. You can wear these around the neck, head, or wrists to reduce your body temperature.

Try also to modify the time or place you exercise; try to find cool shade or air-conditioned areas when possible.

If you have tried these first two steps and your sweating is still affecting your life, talk to your doctor. They can help you figure out the best way to manage it.

3. Medication

Some medications can help regulate your sweating. Unfortunately some can also give you side effects such as a dry mouth, blurred vision, stomach pain or constipation. So talk to your doctor about what’s best for you.

Your GP may also refer you to a dermatologist – a doctor like myself who specialises in skin conditions – who might recommend different treatments, including some of the following.

4. Botulinum toxin injections

Botulinum toxin injections are not just used for cosmetic reasons. They have many applications in medicine, including blocking the nerves that control the sweat glands. They do this for many months.

A dermatologist usually gives the injections. But they’re only subsidised by Medicare in Australia for the armpits and if you have primary hyperhidrosis that hasn’t been controlled by the strongest antiperspirants. These injections are given up to three times a year. It is not subsidised for other conditions, such as an overactive thyroid or for other areas such as the face or hands.

If you don’t qualify, you can have these injections privately, but it will cost you hundreds of dollars per treatment, which can last up to six months.

5. Iontophoresis

This involves using a device that passes a weak electrical current through water to the skin to reducing sweating in the hands, feet or armpits. Scientists aren’t sure exactly how it works.

But this is the only way to control sweating of the hands and feet that does not require drugs, surgery or botulinum toxin injections.

This treatment is not subsidised by Medicare and not all dermatologists provide it. However, you can buy and use your own device, which tends to be cheaper than accessing it privately. You can ask your dermatologist if this is the right option for you.

6. Surgery

There is a procedure to cut certain nerves to the hands that stop them sweating. This is highly effective but can cause sweating to occur elsewhere.

There are also other surgical options, which you can discuss with your doctor.

7. Microwave therapy

This is a newer treatment that zaps your sweat glands to destroy them so they can’t work any more. It’s not super common yet, and it is quite painful. It’s available privately in a few centres.

Michael Freeman, Associate Professor of Dermatology, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dementia is often described as “the long goodbye”. Although the person is still alive, dementia slowly and irreversibly chips away at their memories and the qualities that make someone “them”.

Dementia eventually takes away the person’s ability to communicate, eat and drink on their own, understand where they are, and recognise family members.

Since as early as the 19th century, stories from loved ones, caregivers and health-care workers have described some people with dementia suddenly becoming lucid. They have described the person engaging in meaningful conversation, sharing memories that were assumed to have been lost, making jokes, and even requesting meals.

It is estimated 43% of people who experience this brief lucidity die within 24 hours, and 84% within a week.

Why does this happen?

Terminal lucidity or paradoxical lucidity?

In 2009, researchers Michael Nahm and Bruce Greyson coined the term “terminal lucidity”, since these lucid episodes often occurred shortly before death.

But not all lucid episodes indicate death is imminent. One study found many people with advanced dementia will show brief glimmers of their old selves more than six months before death.

Lucidity has also been reported in other conditions that affect the brain or thinking skills, such as meningitis, schizophrenia, and in people with brain tumours or who have sustained a brain injury.

Moments of lucidity that do not necessarily indicate death are sometimes called paradoxical lucidity. It is considered paradoxical as it defies the expected course of neurodegenerative diseases such as dementia.

But it’s important to note these episodes of lucidity are temporary and sadly do not represent a reversal of neurodegenerative disease.

Why does terminal lucidity happen?

Scientists have struggled to explain why terminal lucidity happens. Some episodes of lucidity have been reported to occur in the presence of loved ones. Others have reported that music can sometimes improve lucidity. But many episodes of lucidity do not have a distinct trigger.

A research team from New York University speculated that changes in brain activity before death may cause terminal lucidity. But this doesn’t fully explain why people suddenly recover abilities that were assumed to be lost.

Paradoxical and terminal lucidity are also very difficult to study. Not everyone with advanced dementia will experience episodes of lucidity before death. Lucid episodes are also unpredictable and typically occur without a particular trigger.

And as terminal lucidity can be a joyous time for those who witness the episode, it would be unethical for scientists to use that time to conduct their research. At the time of death, it’s also difficult for scientists to interview caregivers about any lucid moments that may have occurred.

Explanations for terminal lucidity extend beyond science. These moments of mental clarity may be a way for the dying person to say final goodbyes, gain closure before death, and reconnect with family and friends. Some believe episodes of terminal lucidity are representative of the person connecting with an afterlife.

Why is it important to know about terminal lucidity?

People can have a variety of reactions to seeing terminal lucidity in a person with advanced dementia. While some will experience it as being peaceful and bittersweet, others may find it deeply confusing and upsetting. There may also be an urge to modify care plans and request lifesaving measures for the dying person.

Being aware of terminal lucidity can help loved ones understand it is part of the dying process, acknowledge the person with dementia will not recover, and allow them to make the most of the time they have with the lucid person.

For those who witness it, terminal lucidity can be a final, precious opportunity to reconnect with the person that existed before dementia took hold and the “long goodbye” began.

Yen Ying Lim, Associate Professor, Turner Institute for Brain and Mental Health, Monash University and Diny Thomson, PhD (Clinical Neuropsychology) Candidate and Provisional Psychologist, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.