Insomnia almost never comes from a single cause. It is usually a combination of factors — physical, psychological and behavioural — that lock together into a self-feeding cycle. To understand how to get out of insomnia, you first need to understand how it started, and above all what is keeping it going now. That is exactly where CBT-I, the first-line treatment recommended by NICE and the NHS, focuses.
Many people who come for help with insomnia ask the same question: “Why is this happening to me?” I used to sleep fine. Nothing catastrophic happened. So how did I reach a point where the night has become a struggle? The simple truth is that insomnia rarely has one cause — and most of the causes can be changed.
Stress and pressure — the most common trigger
For many people, insomnia begins during a period of strain: work, study, a personal crisis, illness, the birth of a child or a significant life change. Stress switches on the body’s emergency system — the very system designed to help us survive, not to fall asleep.
Even after the stressful period passes, the body sometimes “forgets” how to switch off that alertness. Sleep doesn’t return automatically, and the sleepless nights begin to provoke fear and worry in their own right.
Thoughts and sleep anxiety — when the mind becomes the enemy
One of the central drivers of insomnia is not what happens during the day, but what happens in your head at night. Thoughts such as “if I don’t sleep now, I’ll be wrecked tomorrow”, “I must fall asleep”, or “here it goes again” sound perfectly logical — but in practice they activate the body, raise the heart rate and tension, and push sleep even further away. At this point it is no longer just a lack of sleep, but sleep anxiety, one of the central challenges in any insomnia treatment.
Unhelpful habits that worsen insomnia
Often, in trying to cope with tiredness, we develop habits that help in the short term but strengthen the problem in the long term:
- Going to bed too early “to make sure I get enough sleep”
- Staying in bed for hours while awake
- Long daytime naps
- Using screens in bed
- Relying on sleeping tablets or fixed rituals
Habits like these disrupt the natural sleep drive and teach the brain that bed equals wakefulness, worry and struggle.
Medical and physiological causes
Sometimes insomnia is linked to physical factors such as chronic pain, hormonal changes (as in the menopause), sleep apnoea, restless legs syndrome or certain medications. In these cases appropriate medical treatment matters — but even then, a layer of behavioural insomnia often develops on top, requiring its own focused treatment.
Mental state: anxiety, depression and trauma
Insomnia very commonly occurs alongside anxiety, depression or trauma. Sometimes it begins because of the emotional state, and sometimes it is what makes that state worse, creating a cycle: low mood → poor sleep → worsening mood → even less sleep. For this reason, treating insomnia is often a meaningful key to broader improvement in mental wellbeing.
So why doesn’t it just “go away on its own”?
Because after a few weeks or months, insomnia no longer depends only on the original trigger. It becomes a learned pattern of wakefulness, effort and fear around sleep. This is exactly where professional treatment comes in. The most effective treatment for chronic insomnia is CBT-I, which focuses not just on “sleeping more” but on dismantling sleep anxiety, changing the habits that hold the problem in place, strengthening the natural sleep drive and restoring confidence in your ability to sleep.
In summary
Insomnia is not a weakness and not a sentence handed down from above. It is the result of a combination of factors — and most of them can be changed. When sleep stops being a struggle, the body remembers, by itself, how to do what it has always known how to do.