Cramps in your 30s may be related to being cold, or may be caused by calcium deficiency, epilepsy and other reasons. 1. Cold: If you stay in a cold environment for a long time in your 30s, it will cause your local muscles to be stimulated by cold, which will easily cause local muscle spasm and contraction, and thus may cause cramps. 2. Calcium deficiency: 30s if long-term poor dietary habits, excessive partiality, picky eating, resulting in a lack of nutrients, especially when the lack of calcium, resulting in low blood calcium levels, easy to cause muscle spasms, which may cause cramping symptoms. 3. Epilepsy: Partial seizures can be characterized by involuntary twitching of one side of the limbs, which can generally be diagnosed with the help of an EEG. Cramps in the 30s may also be caused by other reasons, it is recommended to seek medical attention as soon as possible to clarify the cause of the disease, and then give targeted treatment and conditioning.