The Achilles tendon is the combined tendon of the two calf muscles, the gastrocnemius and soleus.
Although it is the strongest tendon in the body, it can sometimes be overloaded, which causes discomfort and even pain.
Achilles pain used to be called Achilles tendinitis but we now know that the Achilles does not get inflamed, so we use the term Achilles tendinopathy. Achilles tendinopathy is typically seen in running or jumping activities but can occur in people who don’t play sport.
General tightness can also be seen in summer months when people wear shoes with no heel e.g. flat sandals/flip flops that put an extra stretching load on the Achilles. Occasionally this can develop into a tendinopathy.
When the tendon is overloaded it tends to get thicker/swollen, usually in the middle of the tendon about 5cm above where the Achilles inserts into the heel bone (calcaneum). Typically the Achilles will feel tight and sore first thing in the morning and when you first start exercising. In the early stages that pain will often ease off once the Achilles is warmed up. During exercise the pain will usually recur as the Achilles gets tired and this pain may persist once exercise has stopped.
Very rarely the outside sheath of the Achilles tendon (the paratenon) can be inflamed with diffuse swelling and a crunchy feel (called crepitus) when touched, but this condition is much less common and will not be discussed further. If you suspect you have this problem consult your GP.
If pain persists ultrasound scan provides helpful information. Please note there is poor correlation between the severity of pain and abnormal findings on scans