If an individual presented with an increasing headache, nausea, vomiting, and swelling in the hands and feet, what is the individual's possible condition?

If an individual has these symptoms, his possible condition is (exertional) hyponatremia.
Hyponatremia means that the level of sodium (Na) in your blood is very low. This is often caused by dehydration, so it is important to drink a lot of water daily. These could be the symptoms, but they can also be more severe, such as confusion, seizures, and coma. 

The correct answer is c