|Insomnia is difficulty getting to sleep or staying asleep for long enough to feel refreshed the next morning. Most people experience problems sleeping at some point in their life. It tends to be more common in women and more likely to occur with age. It's difficult to define a normal sleep because everyone is different. Lifestyle, Age, environment and diet all play a part in influencing the amount of sleep one need. The common symptoms of insomnia are: difficulty falling asleep, waking up during the night, waking up early in the morning, feeling irritable and tired and finding it difficult to function during the day. There is a range of things that can help in getting a good sleep such as: avoiding caffeine later in the day avoiding heavy meals late at night setting regular times to wake up using thick curtains or blinds, an eye mask and earplugs to stop you being woken up by light and noise. Sleep aids can be effective for an occasional sleepless night. Most over-the-counter sleep aids contain antihistamines. Tolerance to the sedative effects of antihistamines can develop quickly so the longer you take them, the less likely they are to make you sleepy. In addition, some over-the-counter sleep aids can leave you feeling groggy, dizzy and unwell the next day. This is the so-called hangover effect. Medication interactions are possible as well, and much remains unknown about the safety and effectiveness of over-the-counter sleep aids.