Ears Sound
Autophony
Your own voice, breathing, or heartbeat sounds far too loud inside your head. It usually means a tube or a thin patch of bone is letting sound take a shortcut into the ear.
About 0.3–6.6% for patulous Eustachian tube
Get it checked
14 oddities.
Spiritual 6Icky 4Not an emergency 20Get it checked 14Try it 62Learnable 20Party trick 19Vestigial 7Genetic 35Sleep 6Illusion 21Childhood 10Debunked myth 11Community 13Famous people 14Record 7
Mouth Variation
Bifid uvula
The uvula, the dangling flap at the back of the throat, is split into two lobes, in about 1 to 2% of people. On its own it is harmless, but in a baby it can be a clue to a hidden cleft of the palate.
1–2% of people
Ears Involuntary
BPPV
A short, intense spinning feeling set off by turning over in bed or tipping your head back. Tiny crystals in the inner ear have drifted into the wrong place. It is the most common cause of vertigo and it is very treatable.
About 2.4% of people, lifetime
Eyes Variation
Distichiasis
A second row of eyelashes growing from the oil-gland openings along the inner edge of the eyelid. It is rare, mostly inherited, and Elizabeth Taylor was born with it.
Rare
Eyes Involuntary
Floaters
Small grey threads, dots, or cobwebs that drift across your vision and dart away when you look at them. They are shadows of tiny clumps inside the eye. They are common and usually harmless.
About 70% of people, at some point
Mouth Involuntary
Inability to burp
Some people have never burped in their lives. Gas cannot pass a ring of muscle at the top of the food pipe, so it stays trapped. This causes gurgling, bloating, and painful pressure. Since 2019 it has a name and a treatment.
Unknown; probably uncommon
Bones Variation
Joint hypermobility
About 1 in 5 people have joints that bend further than usual, measured with a nine-point test called the Beighton score. For most people it causes no trouble.
10–25% of people
Brain Involuntary
Migraine aura
A shimmering zigzag or C-shaped patch of light that grows across your vision over 5 to 60 minutes and then fades. It can come before a migraine headache or, in some people, with no headache at all.
About 3% of people
Eyes Perception
Palinopsia
An image that keeps appearing after the thing you saw is gone. Brief trails behind moving objects are common and harmless. Copies that persist or return minutes later need a doctor.
Brief trailing is common. Persistent forms are rare.
Ears Variation
Preauricular pit
A tiny hole in the skin just in front of the ear, present from birth, that leads to a short blind tunnel. It is harmless unless it gets infected.
0.1–10% of people
Ears Sound
Pulsatile tinnitus
A whooshing or thumping in one ear that keeps time with your pulse. It is the sound of blood flowing near the ear. It is usually harmless, but it always deserves a check-up.
About 3–5% of people with tinnitus
Ears Involuntary
Tinnitus
A ringing, hissing, buzzing, or roaring sound with no source outside your head. Between 15% and 20% of people have it. It is mostly the hearing system filling in for damaged or tired inner-ear cells.
About 15–20% of people
Brain Involuntary
Visual snow
Tiny flickering dots across the whole field of vision, like static on an old TV, present with eyes open or closed. About 2–3% of people have it. The eyes are fine. The visual part of the brain is over-active.
About 2–3% of people
Bones Trick
Voluntary joint dislocation
Pushing a joint partly or fully out of its socket on purpose, then back in. About 20% of people have some joint hypermobility. True voluntary dislocation is much rarer and often linked to a connective tissue disorder.
Rare; no formal count Icky