How long should I leave a lump before getting it checked?
Three weeks is the usual dividing line. A tender lump in the neck, armpit or groin that appeared alongside an infection and is getting smaller is behaving normally. Anything still present after three weeks, growing, hard, fixed in place, or painless, should be assessed rather than watched.
Two exceptions that should not wait three weeks at all: a lump in a testicle, and a new breast lump.
It doesn't hurt. Isn't that a good sign?
No — and this is the most common misunderstanding about lumps. Pain usually indicates infection or inflammation, both of which tend to be benign and self-limiting. The concerning pattern is the opposite: a painless, hard, gradually enlarging lump that is fixed to what lies beneath it. "It doesn't hurt, so I left it" is a familiar sentence in cancer clinics.
Can I just keep an eye on it?
Watching is reasonable for a short defined period with a clear end date — not indefinitely, and not by repeatedly feeling it, which inflames the area and destroys your own comparison. Set a date three weeks out. If it has not gone by then, get it looked at rather than resetting the clock.
Is it just a cyst?
Very possibly. Sebaceous cysts (soft, mobile, often with a small central dot, sometimes discharging cheesy material) and lipomas (soft, rubbery, doughy fatty lumps that move easily) are extremely common and entirely benign. Both can be left alone or removed if they bother you. What distinguishes them is that they are soft and mobile — a hard, fixed lump is not one of these.
I always get lumps in my neck when I'm ill.
That is reactive lymph node enlargement, and it is exactly what lymph nodes are for. They swell during infection and shrink afterwards. The pattern that matters is a node that keeps growing, is rubbery-hard and painless, sits above the collarbone, or comes with night sweats, fever or weight loss.
I've found a lump in my testicle.
Get it assessed this week — do not wait. Most testicular lumps are benign cysts, but testicular cancer is the commonest cancer in men aged 15–45 and it is highly curable when caught early. It is typically painless, which is exactly why it gets left. An ultrasound settles it quickly.
What about a lump in the groin?
Common causes are enlarged lymph nodes and hernias. A groin lump that bulges when you cough or strain and disappears when you lie down is usually a hernia — which needs a surgical opinion, but not urgently. A groin lump that becomes hard, exquisitely painful and cannot be pushed back is an emergency, because a hernia can strangulate.
What happens at the assessment?
The consultation establishes the history — how long, whether it is changing, whether anything preceded it, and whether there are other symptoms — and the site and behaviour of the lump usually narrow it considerably. We can arrange blood tests and an ultrasound, which is the single most useful investigation for most lumps, and refer where needed.
What we cannot do is feel it, and for lumps that is a real limitation — the texture and mobility of a lump carry a lot of information. We will say so where examination is what decides it, rather than working around it.