Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Go to an emergency department if the foreskin is trapped behind the penis head and cannot be brought forward, especially if the head is painful or swollen.
This is called paraphimosis and can restrict blood flow.
Emergency care is also appropriate after a significant injury with severe swelling or uncontrolled bleeding.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek same-day medical advice for severe pain, rapidly increasing swelling, fever, pus, spreading redness, or difficulty passing urine.
3
Does any of this apply?
Book an appointment
Arrange a routine appointment with a doctor or sexual health clinic if a lump or spot:
Is new and has no clear explanation
Lasts longer than two weeks
Grows, changes colour, bleeds, or becomes ulcerated
Returns repeatedly or is spreading
Causes pain, itching, discharge, or foreskin tightening
Appeared after sexual contact or may be an STI
And for anyone, someone who:
has noticed a lump, a mole that has changed, or unexplained weight loss
Every sign above is quoted from the sofidex article on Penis lumps and spots. If you are not sure, err upward — it is always reasonable to be checked.