2 The effects of poor sleep
The effects of poor sleep can vary widely across individuals. We all need different amounts of sleep. Some people can thrive on no more than four hours’ sleep a night while others need as many as nine hours a night.
However, getting fewer than 7 hours of sleep regularly can eventually lead to health consequences that affect your entire body (Healthline, 2023), as shown in Table 1.
| Tiredness | Poor decision-making | Poor digestion and bloating | Increased risk of heart disease |
| Increased anxiety | Reduced long-term memory | Over- or under-eating | Increased blood pressure |
| Low mood | Reduced short-term memory | Weight gain | Type II diabetes |
| Depression | Irritability and grumpiness | Obesity | Clumsiness |
| Difficulty concentrating | Reduced sex drive | Weakened immunity | Increased risk of accidents |
Sometimes the expectation that we should sleep ‘straight through’ can be unhelpful, as this isn’t normal. It is absolutely normal to ‘wake up’ up to five times a night. This occurs when we complete a sleep cycle (about 1.5 hours) and rise up to near consciousness before falling into the next sleep cycle. But when we wake, we should fall back to sleep very quickly, sometimes so quickly that we are barely aware we have been awake. When we wake and can’t get back to sleep is when the problems start.