According to the Merck Manual, there are two types of decompression sickness. Type 1, commonly called bends, is less hard and causes pain in the joints. Sometimes symptoms include fatigue, itching, rashes, and swelling in the abdomen, arms, or chest. Type 1 decompression sickness is often called bends because the gas bubbles affect your joints, causing them to lock up and lose mobility (via Britannica). Type 2 decompression sickness can be fatal and affects the nervous system, writes Merck Manual. There is a wide range of symptoms including but not limited to confusion, double vision, difficulty breathing, headache, hearing loss, inability to urinate, numbness, paralysis, dizziness and weakness. Healthline notes that type 2 decompression sickness is sometimes called strangulation.
Healthline says treatments for decompression sickness include breathing pure oxygen for less severe cases, while more severe cases are treated with recompression, otherwise known as hyperbaric oxygen therapy — where you breathe oxygen pure in a pressurized chamber (by Mayo Clinic).
To help prevent decompression sickness, the Merck Handbook recommends not flying within a day of diving, even if you are on vacation. Some divers try to prevent decompression sickness by minimizing the time spent underwater and the depth of the dive. You can also make decompression stops during the ascent to the surface.