Your body is begging for electrolytes if you have one of the following symptoms: slower thinking, loss of memory, fatigue is an electrolyte deficiency. It's electrolytes that help power the nervous system, which includes the brain. Any twitching you have in your body, muscle spasm, or muscle tightness is an electrolyte deficiency. Problems with the rhythm of your heart or sugar cravings can also be an electrolyte deficiency. When you don't have enough potassium or magnesium, you're going to want more sugar. If you have poor performance with exercise, suspect an electrolyte deficiency. When you get on a ketogenic diet, you get rid of a lot of fluid, and with the fluid loss comes electrolyte loss. Water retention can also be an electrolyte deficiency. When you're low in especially potassium, you're going to fill up with more sodium. To reduce your risk for kidney stones, increase your potassium and magnesium. If you have headaches, suspect an electrolyte deficiency, especially sodium.