Shivering is medically known as tremors, which are regular recurrent unself-helpful body shakes that can occur all over the body, mostly in the extremities, and can be large or small in amplitude and fast or slow in speed. Generally between 1-10 times per second. Common causes include physiologic tremors, somatic or hereditary tremors, Parkinson’s disease tremors, and tremors caused by cerebellar lesions, while physiologic tremors are normal physiologic phenomena rather than diseases. The tremor is small and rapid. It is present in all normal people, but it is usually not noticeable and cannot be detected on its own. In some cases, the physiological tremor can be intensified and become very strong and pronounced. Common causes include emotional stress, fear, cold, low blood sugar, hyperthyroidism, alcohol or drug withdrawal symptoms, and the effects of drugs or caffeine. Additionally somatic or hereditary tremors can occur at all ages, but the older you get, the tremors can be very severe. It occurs mainly in the hands, but also in the head, and even in the voice. It is particularly noticeable when the hands are in a fixed position or when performing fine movements. The tremor is relieved by rest. In some cases, the tremor decreases after drinking alcohol. The course of this tremor worsens slowly and no other symptoms occur. In Parkinson’s disease, the tremor occurs mainly in the elderly and is particularly noticeable in the hands and feet at rest, and gradually decreases when sitting. This feature is the opposite of institutional or hereditary tremors. If the lesion continues to worsen, other neuropsychiatric symptoms may occur. In the case of tremors caused by cerebellar lesions, they are absent or very mild at rest, and are mild when maintaining a fixed position, becoming more pronounced the closer the target is to the target, and are called disequilibrium.