What causes the big toe to swell?

Various answers: This may be caused by gout if the toe is red, hot and swollen that you can barely touch it. An ingrown toenail will have swelling and pain on the side of the nail. A broken bone or contusion will cause a deeper bone pain upon pushing to the area. For a more definitive answer, see your podiatrist.

Depends on cause: Some causes of swelling can include systemic problems such as hypertension, and problems with the kidneys and localized issues such as arthritis, infection, lymphatic obstruction, blood clots, varicose veins, trauma (fracture, sprain, tendonitis, tight shoes) and side effects to medication. Have it evaluated by a professional and get the appropriate treatment.