It’s the morning after a big night and you’re feeling the effects of too much alcohol.

So it can be tempting to “refresh” and take the edge off a hangover with a swim at the beach, or a dip in the cool waters of your local river or pool.

But you might want to think twice.

The day after heavy drinking can affect your body, energy levels and perception of risk in many ways. This means you’re more likely to drown or make careless decisions – even without high levels of alcohol in your blood.

Alcohol + water + summer = drowning

Alcohol is one of the main reasons why someone’s more likely to die due to drowning. And Australians consume a lot of it, including around the water.

The risk of drowning, and injury, including incidents involving alcohol, dramatically increases over the summer festive period – in particular on public holidays and long weekends.

Among people aged 18 and over who drowned in rivers where alcohol was involved, we found some 40% had a blood alcohol concentration of at least 0.20%. That’s four times the upper legal limit of 0.05% when driving a car on a full licence.

When we breathalysed people at four Australian rivers, we found higher levels of blood alcohol with higher temperatures, and particularly on public holidays.

At the beach, intoxication due to alcohol and/or drugs is involved in 23% of drowning deaths with an average blood alcohol concentration of 0.19%.

How about if you’re hungover?

Getting alcohol out of your body is a relatively slow process. On average, alcohol is metabolised at a rate of 0.015% per hour. So if someone stops drinking at 2am with a blood alcohol concentration of 0.20%, their alcohol levels don’t drop to zero until 4pm the next day.

Although hangovers can vary from person to person, typical symptoms include headache, muscle aches, fatigue, weakness, thirst, nausea, stomach pain, vertigo, irritability, sensitivity to light and sound, anxiety, sweating and increased blood pressure.

As well as feeling a bit dusty, the day after an evening of heavy drinking, you’re not so good at identifying risks and reacting to them.

In a pool, this might mean not noticing it’s too shallow to dive safely. In natural waterways, this might mean not noticing a strong river current or a rip current at the beach. Or someone might notice these hazards but swim or dive in anyway.

In one study, we found that after a four-day Australian music festival where people drank heavily, even people who were sober (no longer had alcohol in their blood) were still affected.

Compared to baseline tests in the lab we ran three weeks before the festival, people who were sober the day after the festival had faster reaction times in a test to gauge their attention. But they made more mistakes. This suggests hangovers coupled with fatigue lead to quicker but more careless behaviour.

In and around water this could be the difference between life and death.

Positive blood alcohol readings, including of alcohol from the night before, are commonly implicated in drowning deaths as a result of risky behaviours such as jumping into the water, both at a river and along the coast. Jumping can cause physical injury or render you unconscious, leading to drowning.

Alcohol, including the day after drinking, can also make drowning more likely for a number of other reasons. It also reduces people’s coordination and reaction times.

What else is going on?

Alcohol makes the blood vessels near your skin open up (dilate). So more blood flows into them, making you feel hot. This means you may stay in colder water for longer, increasing your risk of hypothermia.

Alcohol can even make CPR (cardiopulmonary resuscitation) less effective, should you need to be resuscitated.

Normally, your body controls levels of certain minerals (or electrolytes) in the blood. But electrolyte imbalance is common after heavy drinking, including the day after. It’s the reason why hangover symptoms such as muscle pain can lead to cramps in your arms or legs. This can become dangerous when being in or on the water.

Low blood sugar levels the day after drinking is also common. This can lead to people becoming exhausted more quickly when doing physical activities, including swimming.

Other hazards include cold water, high waves and deep water, all of which your body may not be capable of dealing with if you’re feeling the effects of a big night.

What can we do about it?

Authorities regularly warn about the dangers of alcohol intoxication and being near the water. Young people and men are often targeted because these are the groups more likely to drown where alcohol is involved.

Beaches may have alcohol-free zones. Rivers rarely have the same rules, despite similar dangers. https://www.youtube.com/embed/5Salt-kkGUo?wmode=transparent&start=0 Royal Life Saving urges men to ‘make the right call’ and avoid alcohol around the water.

How to stay safe around water if you’re drinking

So take care this summer and stay out of the water if you’re not feeling your best:

• do your swimming before your drinking
• look out for your mates, especially ones who may have had a few too many or are hungover
• avoid getting back into the water after you’ve drunk alcohol or if you’re not feeling your best the next day.

Amy Peden, NHMRC Research Fellow, School of Population Health & co-founder UNSW Beach Safety Research Group, UNSW Sydney; Emmanuel Kuntsche, Director of the Centre for Alcohol Policy Research, La Trobe University, and Jasmin C. Lawes, Adjunct Senior Lecturer, UNSW Beach Safety Research Group, UNSW Sydney

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

What’s the difference? is a new editorial product that explains the similarities and differences between commonly confused health and medical terms, and why they matter.

The term “man flu” takes a humorous poke at men with minor respiratory infections, such as colds, who supposedly exaggerate their symptoms.

According to the stereotype, a man lies on the sofa with a box of tissues. Meanwhile his female partner, also with a snotty nose, carries on working from home, doing the chores and looking after him.

But is man flu real? Is there a valid biological reason behind men’s symptoms or are men just malingering? And how does man flu differ from flu?

What are the similarities?

Man flu could refer to a number of respiratory infections – a cold, flu, even a mild case of COVID. So it’s difficult to compare man flu with flu.

But for simplicity, let’s say man flu is actually a cold. If that’s the case, man flu and flu have some similar features.

Both are caused by viruses (but different ones). Both are improved with rest, fluids, and if needed painkillers, throat lozenges or decongestants to manage symptoms.

Both can share similar symptoms. Typically, more severe symptoms such as fever, body aches, violent shivering and headaches are more common in flu (but sometimes occur in colds). Meanwhile sore throats, runny noses, congestion and sneezing are more common in colds. A cough is common in both.

What are the differences?

Flu is a more serious and sometimes fatal respiratory infection caused by the influenza virus. Colds are caused by various viruses such as rhinoviruses, adenoviruses, and common cold coronaviruses, and are rarely serious.
Colds tend to start gradually while flu tends to start abruptly.

Flu can be detected with laboratory or at-home tests. Man flu is not an official diagnosis.

Severe flu symptoms may be prevented with a vaccine, while cold symptoms cannot.

Serious flu infections may also be prevented or treated with antiviral drugs such as Tamiflu. There are no antivirals for colds.

OK, but is man flu real?

Again, let’s assume man flu is a cold. Do men really have worse colds than women? The picture is complicated.

One study, with the title “Man flu is not a thing”, did in fact show there were differences in men’s and women’s symptoms.

This study looked at symptoms of acute rhinosinusitis. That’s inflammation of the nasal passages and sinuses, which would explain a runny or stuffy nose, a sinus headache or face pain.

When researchers assessed participants at the start of the study, men and women had similar symptoms. But by days five and eight of the study, women had fewer or less-severe symptoms. In other words, women had recovered faster.

But when participants rated their own symptoms, we saw a somewhat different picture. Women rated their symptoms worse than how the researchers rated them at the start, but said they recovered more quickly.

All this suggests men were not exaggerating their symptoms and did indeed recover more slowly. It also suggests women feel their symptoms more strongly at the start.

Why is this happening?

It’s not straightforward to tease out what’s going on biologically.

There are differences in immune responses between men and women that provide a plausible reason for worse symptoms in men.

For instance, women generally produce antibodies more efficiently, so they respond more effectively to vaccination. Other aspects of women’s immune system also appear to work more strongly.

So why do women tend to have stronger immune responses overall? That’s probably partly because women have two X chromosomes while men have one. X chromosomes carry important immune function genes. This gives women the benefit of immune-related genes from two different chromosomes.

Oestrogen (the female sex hormone) also seems to strengthen the immune response, and as levels vary throughout the lifespan, so does the strength of women’s immune systems.

Men are certainly more likely to die from some infectious diseases, such as COVID. But the picture is less clear with other infections such as the flu, where the incidence and mortality between men and women varies widely between countries and particular flu subtypes and outbreaks.

Infection rates and outcomes in men and women can also depend on the way a virus is transmitted, the person’s age, and social and behavioural factors.

For instance, women seem to be more likely to practice protective behaviours such as washing their hands, wearing masks or avoiding crowded indoor spaces. Women are also more likely to seek medical care when ill.

So men aren’t faking it?

Some evidence suggests men are not over-reporting symptoms, and may take longer to clear an infection. So they may experience man flu more harshly than women with a cold.

So cut the men in your life some slack. If they are sick, gender stereotyping is unhelpful, and may discourage men from seeking medical advice.

Thea van de Mortel, Professor, Nursing, School of Nursing and Midwifery, Griffith University

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