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ax·il·lar·y fos·sa

depression between the anterior and posterior axillary folds forming the floor of the axilla; after puberty, this is a site of hair growth and an abundance of sweat glands.
Synonym(s): fossa axillaris [TA], armpit


The hollow under the upper part of the arm at the shoulder.


See axilla.


The depressed hollow region located under the shoulder joint, medial to the upper arm.
Content  Axillary vessels, including the axillary artery (the extension of the subclavian artery, which becomes the brachial artery) and the axillary vein (which arises from the brachial veins and basilica vein and becomes the subclavian vein); axillary nerves; brachial plexus; lymph nodes; fat; loose connective tissue.
Muscles, anterior to posterior Pectoralis major, deltoid, biceps brachii, coracobrachialis, teres major and latissimus dorsi, and long head of triceps.
Medical significance Site of lymphatic drainage from the arm (e.g., for melanomas) and breast (e.g., for breast cancer).
Sports injuries Axillary (nerve) damage is uncommon, but well-described in contacts sports (e.g., from collisions in ice hockey or tackling in American football).

Patient discussion about armpit

Q. A lump in my armpit Hi, Last week after the shower I found a small painful lump in my right groin. I went to see a doctor and he prescribed me some antibiotics. I’ve been taking it for 5 days and the lump is still there. I’m 31, usually healthy and work-out in the gym regularly, don’t smoke or use drugs and don’t take any medications. Is that dangerous? Should I go and see another doctor?

A. What you describe sounds like enlarged lymph node. The first diagnosis that’s suspected in such case is an infection that makes it painful. The antibiotics you take need several more days to act, so currently it doesn’t sound suspicious. If the lump persist, it’d be wise to consult you doctor

Q. I located a lump on the surface of my right underarm. I think I am showing some signs of breast cancer. I am 27 years old working lady. I think I am showing some signs of breast cancer. I located a lump on the surface of my right underarm. This lump is of a cherry size and does not pain at all. But I do have pain in my breast. I had my mammogram done which showed no lump and my doctor says that there is nothing to worry and she has given me some medicines. I want to know that if everything is normal then how come these lumps came.

A. there are ways to diagnose if lumps are breast cancer or not. a lump under the forearm can be a sign of an advanced stage of cancer, but it can also mean some kind of viral infection that caused a lymph node to swell up. so if a doctor told you it's fine- he probably checked it out, and it's fine. if you still anxious - go get a second opinion.

More discussions about armpit
References in periodicals archive ?
It goes on to say that alternative phrases given are chicken skin, labia pit, fungus fold, armpit waddle and rooster arm.
Another added: "I just don't buy the idea that #wonderwoman would shave her armpits, let alone bleach them, as appears to be the case in the trailer.
Actress Julia Roberts accessorised her red-carpet look with hairy armpits in 1999, at the premiere of Notting Hill, and Britney Spears sported underarm hair at the American Music Awards.
Yet a strange cove from the Black Country called Wagner, who looks suspiciously like the gent who fixed our roof, has earned millions of fans with something a lot less melodious than my armpit.
She died from a haemorrhage received from a laceration to the left armpit.
Giving evidence at his trial yesterday, the 43-year-old told how he had simply taken the banana out of his pocket so it didn't get squashed and said he scratched his armpits because he has eczema.
Our armpits are our focus of attention, but they contribute less than one percent of the total sweat.
Margulies said Taylor was fortunate because the bullet narrowly missed vital organs after entering through his armpit -- a vulnerable area not covered by his vest.
But one woman wants to stop being a slave to the shave and dispel the prejudices surrounding hairy armpits and calves like a centre-forward for Caernarfon Town FC.
Then he wants to get a job, save some money, avoid situations that might turn violent and lose the name Armpit.
In Sachar's new book, Small Steps, Armpit is still digging.
One bullet struck officer Stewart in the armpit, just above the edge of his protective vest.