A doctor points out many possible causes (some very serious!) of swelling, pain and redness in just one calf.

If a calf is swollen, red and painful (hurts, aches, or feels crampy), especially if there’s no explanation such as a traumatic injury or snake bite, this could mean a deep vein thrombosis (DVT).

This is actually the first thing an ER doctor will suspect if someone with these symptoms is seen in the emergency room.

An ultrasound will be ordered to check for a DVT, but there are times when a DVT is missed.

Making things even trickier is that “a large portion of patients with an acute DVT don’t present with unilateral calf swelling, pain and redness,” says Kevin Casey, MD, FACS, a vascular surgeon with West Coast Vascular.

Swelling, Pain and Redness in a Calf not the Only Symptoms of DVT

“Clinical manifestations are variable,” says Dr. Casey, “and range from absence of symptoms to massive pitting edema and blanching (a condition called phlegmasia cerulea dolens which is a surgical emergency with a high risk for limb loss).”

Edema is fluid buildup that causes swelling.

Pitting means that if you press on the swollen area with a fingertip or, say, eraser-tip of a pencil, it will leave an obvious indentation that will take longer than five seconds (sometimes up to a few minutes) to vanish.

However, pitting edema doesn’t necessarily mean DVT.

Other DVT Signs

“Signs and symptoms include pain, edema, erythema, tenderness, fever, a Homan’s sign (pain with passive dorsiflexion of the foot), peripheral cyanosis or prominent superficial veins,” says Dr. Casey.

Dorsiflexion is the ankle joint motion of flexing the foot upward. 

“Up to 50% of patients with DVT, however, may lack any specific signs or symptoms.”

What else can swelling, pain and redness in one calf mean?

“The differential is broad and includes muscle strain or tear, Achilles tendonitis, soft tissue trauma/injury, superficial thrombophlebitis, symptomatic varicose veins, lymphedema, arthritis, stress fracture, peripheral arterial disease, renal failure, hepatic disease, heart failure,” says Dr. Casey.

You’ll likely have a memory of an extraneous insult for at least a few of these issues, such as muscle strain or tear, and stress fracture.

If you have kidney, liver or heart failure, you’ll very likely have other troubling symptoms of these conditions.

Blood tests can reveal presence of disease in these organs.

Pain, redness and swelling, especially in one calf, warrants immediate evaluation by a doctor!

Dr. Casey specializes in vascular and vein therapy, and has been the lead researcher on publications examining abdominal aortic aneurysms, carotid artery disease and lower extremity critical limb ischemia.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Shutterstock/ Joyseulay