A heel spur (also known as a calcaneal spur) is a bony outgrowth that you can sometimes see and feel on the underside of your foot. It is made up of calcium deposits and can have a pointy, hooked, or shelf-like shape. There are several causes of heel spurs, but they very often occur in patients with plantar fasciitis,1
or the inflammation of the plantar fascia—the tissue that runs along the bottom of the foot and connects the heel to the toes.
Many people think that heel spurs cause heel pain—but that’s not always the case. According to the Cleveland Clinic, one out of 10 people have heel spurs, but only one out of 20 people with a heel spur experiences heel pain. Others may experience symptoms that include tenderness, a dull ache, or sharp pain when standing.
Most often, it's not the heel spur that causes the pain, but the inflammation and irritation of the plantar fascia. Heel pain is worst in the morning after sleep (some people say it feels like a knife going into the heel), making it difficult to take those first steps out of bed.
This is because the foot is resting in plantar flexion overnight (i.e., your toes are pointed down), which causes the fascia to tighten. As you put pressure on the foot, the fascia stretches, which causes pain. This does subside as you begin to move and loosen the fascia (although you will likely still feel a dull ache), only to return after walking or standing for extended periods.
Other symptoms of heel spurs include:
A small, visible protrusion: On X-rays, a heel spur can be up to a half-inch long.
Inflammation and swelling2
Burning, hot sensation
Tenderness that makes it painful to walk barefoot3
Heel spurs occur in 70 percent of patients with plantar fasciitis.4 The plantar fascia is one of the major transmitters of weight across the foot as you walk or run. When the plantar fascia becomes inflamed, a heel spur can form at the point between the fascia (the tissue that forms the arch of the foot) and the heel bone.
Most common among women, heel spurs can also be related to another underlying condition, including osteoarthritis, reactive arthritis (Reiter’s disease), and ankylosing spondylitis.
Other causes of heel spurs include:
Overuse: Activities like running and jumping, especially if done on hard surfaces, can cause heel spurs by wearing down the heel and arch of the foot.
Obesity: The more weight you carry around, the greater your risk of heel spurs.5
Improper footwear: Ill-fitting or non-supportive footwear (like flip-flops) can cause heel spurs.
Your healthcare professional may ask about your history of heel pain and examine your foot for tenderness at the bottom of the foot, near the heel. She may ask you to flex your foot to assess pain and range of motion. She will also visually examine the heel looking for a protrusion, which may or may not be present.
A heel spur diagnosis is formally made when an X-ray shows the bony protrusion from the bottom of the foot at the point where the plantar fascia is attached to the heel bone.3
Other Possible Causes of Heel Pain
By and large, the treatment of heel spurs is the same as that of plantar fasciitis, with the first step being short-term rest and inflammation control.
For the majority of people, heel spurs do get better with conservative treatment that may include:
Got Plantar Fasciitis? Try These Stretches to Find Relief
The heel spur will not go away with these treatments, but the discomfort it causes can usually be sufficiently controlled with their use.
When that's not the case, cortisone injections may be helpful in some individuals. Surgery to remove the heel spur is rare and only necessary when the trial of (and dedication to) the above treatments have failed.