Ankle and leg cramps at night often occur for unknown reasons, but structural disorders, such as spinal stenosis; medications for blood pressure and cholesterol; or conditions such as dehydration and diarrhea can cause the discomfort, according to Mayo Clinic. Pregnancy and muscle fatigue also cause ankle cramps.
Individuals with nerve damage, pregnancy complications, osteoarthritis and Parkinson's disease often experience ankle and leg cramps, explains Mayo Clinic. The risk of ankle cramps increases with age. An injury to the ankle can also cause cramping at night.
People with metabolic problems experience ankle and leg cramps as well, according to Mayo Clinic. Conditions such as chronic kidney disease, diabetes, cirrhosis and underactive or overactive thyroids increase the risk of cramping at night in the legs and ankles.
Rigorous exercise, overuse of muscles, injury and cold weather can cause ankle cramping in the evening, according to WebMD. People with blood flow problems are more prone to cramping.
Ankle and leg cramps at night are involuntary spasms that produce aching or contractions of muscles in the legs near the ankles, explains Mayo Clinic. Nighttime cramps often involve the muscles, and as a result, some people experience pain in the feet and thighs in addition to the ankles and legs.