• Patients misdiagnosed with CFS when they have brain damage
• Post-traumatic hypopituitarism (PTHP) is often cause by head injury
• Symptoms include depression, obesity, fatigue and chronic pain

Numerous studies have shown that between 20 and 30 per cent of the 135,000 patients who suffer a serious head injury also experience damage to the pituitary gland, which is situated below the brain, behind the nasal cavity.

The gland produces vital hormones that govern many bodily functions, including growth and repair, the sleep-wake cycle and how we react to stress. If the pea-sized organ is damaged, it may stop producing one or more of the essential hormones, triggering the wide-ranging symptoms of hypopituitarism.

Studies suggest there could be between 18,000 and 30,000 cases in the UK each year.

Treatment involves lifelong hormone replacement therapy, which is said to be highly effective but costs up to £6,000 a year.

More information in the Daily Mail: How doctors are failing to spot the brain injury that could be behind 30,000 cases of ‘chronic fatigue’