Compression
This can also be done yourself in your home. Simply wrapping up the part with elastic bondages can be very effective. When the injured part is swollen, it can make it hard to move the area, so compressing the area can help reduce the swelling.
Elevation
This is a piece of simple knowledge that raising the injured part to a high level would help reduce the swelling. For example, if Tendonitis affects the ankle, raise the affected part above the level of your heart to reduce the swelling.
Physical therapy
You can see a physical therapist. There are some prescribed exercises you might benefit from and would help ease the pain. Exercises that could help stretch and strengthen the affected muscle tendon, some exercise programs have been proven to be effective in treating serious tendon conditions that they are now the first spoken off treatment to apply in case of any tendonitis.