You ask a lot from your feet without even realizing it. Your feet give you a steady base to stand on, behave as levers that allow you to move forwards, backwards and sideways, and they absorb shocks when you walk, run, or jump.
Tendonitis could be one reason that you are suffering pain to the outside of your foot. Tendonitis is diffuse pain that is just at the front of your heel on the outside of your foot. It is usually caused by wearing shoes that are too narrow for your feet. This causes the tendon that runs along the outside of your foot and under the cuboid bone to become irritated.
Tailors Bunion is when you get a bony bump on the outside of your foot just behind your pinky toe. Tailors Bunion is caused by an inherited defect that causes an enlargement of the 5th metatarsal bone.
Bursitis can also cause pain on the outside of the foot. Bursitis in the case of the foot is where the body creates a bursal sac, which is a fluid filled sac that lubricates the area between muscles, tendons and bones, to protect an area of the foot that has been micro-traumatized. Unfortunately, sometimes if the micro-trauma continues, the bursal sac will become inflamed causing pain on the outside of the foot.
If you fractured the 5th metatarsal on your foot .then you would feel that pain on the outside of your foot. In the case of a fracture, you would only suspect this if you had no other type of trauma to the foot.
Blisters on the outside of the foot are generally speaking the result of ill-fitting shoes irritating the skin on the outside of the foot. While painful, blisters usually pop on their own and then as long as you keep them clean and covered, they heal relatively quickly.
Fissures are when the skin on the outside of the foot by the heel becomes severely dry and then cracks form deep in the skin. Many times these cracks become inflamed and bleed and can be very painful.
Ganglions are fluid sacs that are created when there is a leak in the joint capsule. These can cause a lot of a pain on the outside of the foot.
Sinus Tarsi Syndrome
Sinus Tarsi Syndrome can cause pain on the side of the foot and to the back behind your ankle. It is usually happens after you have a severe inversion ankle injury, or when the ankle rolls over on the outside and you stretch and tear the ligaments there causing a sprain.