DR MAX PEMBERTON: There is no magic pill for nightmares, but this is the one thing I prescribe to every patient for better sleep

You wake up in a cold sweat, panting, your heart pounding. You scan the dark room covertly. Nothing. You relax: It was just a nightmare. But still that feeling of foggy dread lingers and you struggle to fall back asleep.

We’ve all had nightmares, and they’re never nice to experience. We tend to remember them more than ordinary dreams because they are filled with emotion, and if they are disturbing enough, we wake up midway through, increasing the chances that we can recall them.

Sometimes people come to me and say they are worried about the intensity of their nightmares. But while they tend to be vivid and often menacing or bizarre, in all but a handful of cases, having nightmares is completely normal.

In fact, nightmares are thought to be a form of emotional processing. They are our brain’s way of trying to sort through and understand something that is troubling us – a means of exploring fears or anxieties or grappling with memories of events that have caused us distress and are sometimes too big, complex or upsetting to think about on when we are awake.

Interestingly, the risk of having nightmares is increased in certain physical conditions – such as when you have a fever or when you have eaten right before bed.

The theory is that both things stimulate the body’s metabolism and make the brain more active.

Certain medications also increase the chance of them occurring, as do mental health problems such as depression or anxiety.

More than 80 percent of people with PTSD report nightmares. In healthy people, their frequency is thought to decrease with age.

They are most common in children aged three to six, and then fall off as we get older. Still, about 5-8 percent of adults report problems with nightmares, and for some they can be a real threat.

Nightmare disorder is a true sleep disorder (also called parasomnia) in which nightmares occur so frequently that they interfere with your sleep, mood and daytime functioning.

Not only do sufferers wake up feeling scared and anxious, which can prevent them from falling asleep easily, but in some cases they are so afraid of a recurrence that they delay going to bed.

The problem is that this kind of sleep avoidance only serves to make the situation worse. They are so exhausted and sleep-deprived that the normal sleep cycle is disrupted, triggering even more intense dreams and nightmares.

Of course, it can affect people’s mental health, increasing depression and anxiety, increasing the risk of more nightmares. While there is sometimes a clear underlying factor that contributes to the malignant appearance of a bad dream—for example, a traumatic event—this is not always the case.

Often psychotherapy can help uncover hidden causes and address them, but sometimes when no clear cause can be found, recurring nightmares can be difficult to treat.

Some therapy techniques focus on improving people’s sleep hygiene, thereby improving the quality of sleep they get, which can help overall.

Simple things like avoiding alcohol and caffeine before bed, as well as putting away screens at least an hour before turning in, can all prepare the brain for restful sleep.

Patients often ask if there is a pill I can prescribe. But unfortunately, there is no reliable anti-nightmare medication out there.

But over the years, I’ve found a remedy that really seems to help: exercise. I often recommend it to patients, and last week a study confirmed that this advice works.

Researchers from the University of Texas found that when people got at least 60 minutes of physical activity during the day, they not only slept better at night, but spent less time in the period of sleep where dreams and nightmares take place – REM, or rapid eye movement, sleep.

By making ourselves less physiologically vulnerable to nightmares—literally cutting down the time they have to occur—we might be able to avoid them.

It often comes down to a number of different approaches to tackling nightmares, but an hour of exercise a day seems like a very good place to start.

Vaping has been linked to a 20 percent increased risk of heart failure, according to a study. But don’t let these statistics put you off if you’re trying to quit smoking cigarettes. Vaping is still far less risky than tobacco.

Ellie right to pause her social media

Singer Ellie Goulding took a break from Instagram following the break-up of her marriage to art dealer Caspar Jopling, temporarily deleting her account, which has nearly 14 million followers.

What a sensible thing to do. For some people going through a difficult program, social media can feel like a source of support. But all too often it is harmful.

When patients are struggling, one piece of advice I often give is to get off social media. If you’re in a fragile state, a few unkind, catty or thoughtless comments can send you spiraling; and its fake, sanitized version of the world often makes you feel worse about your own.

Who wants to see pictures of other people howling with the love of their life when you’re going through a breakup?

A decade or so ago, women were bombarded with scare stories about HRT. The increased risk of breast cancer, stroke and heart attack was well documented – or so it seemed – and doctors were wary of prescribing it.

But over the past few years, further analysis of the research has shown that some of it has overstated the risks. At the same time, several celebrities have become vocal advocates of HRT, describing how it helped them cope with the unwanted effects of menopause.

Now a new study has shown a particular physical benefit that should not be underestimated.

A precipitous drop in estrogen during menopause triggers plaque buildup in the arteries, leading to a steep increase in the risk of heart problems.

However, HRT, which stops this sudden drop, has been shown to reduce the risk of heart disease in women who take it.

Dr. Max prescribes… Hay fever balm

Spring finally seems to have arrived – but with this comes a rise in pollen levels and, for some, the inevitable misery of hayfever.

The medicated-free HayMax conditioner (£8.49, hollandandbarratt.com) is rubbed around the nostrils and works by capturing more than a third of the pollen before it is inhaled. It also works if you have dust or pet allergens.