C4 to C6 refers to the fourth to sixth cervical vertebrae in the human spine, located in the neck region. These vertebrae play a crucial role in supporting the head and allowing for a range of motion, including bending and rotating the neck. They also protect the spinal cord, which runs through the vertebral column. Injuries or conditions affecting the C4 to C6 vertebrae can lead to pain, limited mobility, or neurological issues. Common problems include herniated discs, fractures, or degenerative diseases. Treatment options may involve physical therapy, medication, or, in severe cases, surgery to alleviate symptoms and restore function.