There are three main types of insomnia, says Andrea Peterson from the Wall Street Journal.
Others wake up too early, which can be associated with depression.
But there are a large number of people who struggle with waking up in the middle of the night. Research found that in 61% of people with insomnia, this was a huge issue.
According to experts, this type of insomnia could signal health issues such as sleep apnea or gastrointestinal problems.
Menopausal women may be woken up with hot flushes caused by the menopause and in older men, prostate issues can result in frequent urination, meaning you wake up more.
Peterson says the best thing to do if you suffer from this type of insomnia is to "do nothing".
This means: don't have a lie in the next day, don't go to bed early and don't nap, because if you start to do these things you may transition from acute to chronic insomnia.
"You basically throw off your whole sleep cycle so it actually becomes more difficult to sleep the next night and the night after that," says Peterson.
Here are her six tips to improve your sleep:
Steer clear of any light or activity that's going to "rev you up".
If you go to the toilet, don't turn on the main light in your bathroom as that will wake you up. Instead, use a plug-in night light.
If you decide to watch TV in the middle of the night, do it with sunglasses on.
Be wary of your pets. If your dogs or cats sleep on the bed, then your rest will almost certainly be disrupted.
Avoid midnight snacks.
Try not to drink alcohol before bed.