In reply to Ridge:
I had achilles tendonitis 18 months ago, and it was excruciating.
To the point of not being able to walk in the mornings after it had been rested.
If it gets worse you need the physio, that hour of massaging and 'working, it helped me tonnes.
Other than that do regular stretches. with your palms flat against a wall, push the leg in question backwards with your sole flat on the floor and slightly bend your front knee until you feel your achilles stretching.
Also do this stretch with the toes on your 'bad' leg facing '10 0clock and 2 oclock' if that makes sense.
Leg raises on a step, where your heel can dip slightly below the step your stood on. Doing so one your affected leg only will prob be too painful so if need be do so using both legs.
Just some exercises the physio showed me.
putting a foam or padded insert into the heal area of your shoe releaves some strain from your achilles and volterene anti inflamatory gel helps a little.
Hth
Allan