Hip arthritis may cause weakness in the thighs, but it can also be the result of a herniated disc in the lower back, excessive exercise, etc. Hip arthritis can present with intermittent or constant pain, and most people will experience pain in areas such as the inner thighs and the back of the buttocks, which may also radiate to the knees. When joint pain occurs, it can lead to decreased mobility and muscle atrophy, which can cause weakness in the thighs. When the disease is severe, the patient may also experience claudication. As the disease gradually worsens, the symptoms of claudication will get worse, resulting in the inability to walk or even being bedridden. In addition, thigh weakness can also be caused by lumbar disc herniation, due to the herniated lumbar disc compressing the nerve root innervating the thigh area, which can cause thigh weakness. Thigh weakness can also be caused by excessive exercise, resulting in the accumulation of lactic acid in the legs, which can be relieved after rest. There are many other causes of thigh weakness, if not relieved after rest, it is recommended to go to the hospital in a timely manner, complete the relevant examinations, to clarify the cause of the disease and then follow the doctor’s instructions for targeted treatment, so as not to delay the condition.