Phlebitis

Also called Superficial thrombophlebitis or Superficial vein thrombosis

Phlebitis (superficial thrombophlebitis) is when a vein just under the skin becomes inflamed, often with a small blood clot. It usually affects the legs, often in varicose veins, but can happen in the arm after a drip or injection. Pregnancy, the contraceptive pill, being inactive and some conditions raise the risk.

Last updated Nov 9, 2026

What it is

It usually gets better within 2 to 6 weeks. Painkillers, warm compresses and raising the leg can help.

Sometimes it is linked to a deeper clot (deep vein thrombosis), so a scan or blood-thinning medicine may be needed.

Common signs

  • A painful, tender vein
  • Redness and warmth along the vein
  • A hard, cord-like vein
  • Swelling around the area
  • Itching

How it is usually diagnosed

  • Examination
  • Ultrasound scan to check for a deeper clot
  • Sometimes blood tests

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Ultrasound reports
  • GP notes
  • Prescriptions

Questions to ask your doctor

  • Is there any sign of a deeper clot?
  • Do I need blood-thinning medicine?
  • How can I stop it happening again?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • Sudden breathlessness, chest pain or coughing up blood: call 112
  • A whole leg that becomes swollen and painful: get urgent help the same day

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

Sources