Insomnia is one of the most talked-about sleep problems, but it's also one of the most misunderstood

Even a single night of sleep trouble can feel distressing and lonely. You toss and turn, stare at the ceiling, and wonder how you'll cope tomorrow. No wonder many people start to worry they've developed insomnia.

Insomnia is one of the most talked-about sleep problems, but it's also one of the most misunderstood.

But just because you can't sleep, it doesn't mean you have insomnia. You might have another sleep disorder, or none at all.

What is insomnia?

Sleep problems can involve being awake when you want to be asleep. This could be lying in bed for ages trying to fall asleep, waking in the middle of the night for hours, or waking up too early. Having a sleep problem is a subjective experience - you don't need to tally up lost hours to prove it's a problem.

But insomnia is the official term to describe a more problematic and persistent pattern of sleep difficulties. And this long-term or chronic sleep disorder has clear diagnostic criteria, which include at least 3 nights a week of poor sleep, lasting three months or more. Insomnia disorder is a longer-term, persistent problem.

Here some reasons why a sleep problem might not be insomnia.

Short term

About a third of adults will have a bout of 'acute insomnia' in a given year. This short-term problem is typically triggered by stress, illness or big life changes. The good news is that about 72% of people with acute insomnia return to normal sleep after a few weeks.

No side-effect

It doesn't affect you the next day. Some people lie awake at night but still function well during the day. In that case, it isn't insomnia. For people with insomnia, the struggle with sleep spills into the day and affects their mood, energy, concentration and well-being. Worry and distress about not sleeping can then make the problem worse, which creates a frustrating cycle of worrying and not sleeping.

More about work or caring

If you feel tired during the day, an important question is whether you're giving yourself enough time to sleep. Work schedules, child care, or late-night commitments can cut sleep short, and sleep can slip down the priority list. In these cases, the problem is insufficient sleep, not insomnia. The average healthy adult gets around seven hours sleep (though this varies widely).

Another disorder

Other sleep disorders can look like insomnia. Obstructive sleep apnoea is when your breathing stops multiple times during sleep. This can cause frequent awakenings through the night and daytime sleepiness. Restless leg syndrome creates an irresistible urge to move your legs that often interferes with falling asleep. Circadian rhythm problems, such as being a natural night owl in an early-bird world, can also lead to trouble falling asleep.

Medications, other substances

Caffeine, alcohol and nicotine all create insomnia symptoms and worsen the quality of sleep. Certain medications can also interfere with sleep, such as stimulants for ADHD and beta-blockers (for various heart conditions). These issues need to be considered before labelling the problem as insomnia.

Getting the right help

If your sleep is worrying you, the best first step is to see a doctor. He/She can help rule out other causes, review your medications, or refer you for a sleep study if needed.

However, once insomnia becomes frequent, chronic (long term) and distressing, you can worry too much about your sleep, constantly check or track your sleep, or try too hard to sleep, for instance by spending too much time in bed. These psychological and behavioural mechanisms can backfire, and make good sleep even less likely.

If you're in a rough patch of sleep:

· remind yourself that short runs of poor sleep usually settle on their own

· avoid lying in bed panicking if you wake at 3.30am. Instead, step out of bed or use the time in a way that feels restful

· keep a consistent wake-up time, even after a poor night. Try to get some morning sunlight to reset your body clock

· make sure you're putting aside the right amount of time for sleep - not too little, not too much.