Most people don't know if they have a hidden extra organ. But they're surprisingly common and often harmless.
Some people have terrifying delusions they are infested with insects, spiders or even small animals. But help is available.
Rapunzel syndrome is an extremely rare medical condition where hairs the person has eaten become tangled and trapped in their stomach.
Gigantism and acromegaly are rare conditions where a benign tumour causes excessive production of growth hormone (GH), which stimulates the growth of the skeleton and all tissues in the body.