Sinking of the legs when walking: First of all, it may be caused by overwork, such as patients with prolonged heavy physical labor, it may cause lower limb pain, limb weakness symptoms. In addition, it may be caused by viral infections, such as viral colds, in addition to the symptoms of the common cold, during the cold, there may also be symptoms of limb weakness, body aches and pains. Patients suffering from hypothyroidism and other diseases are also prone to fatigue due to a lower basal metabolic rate, and may experience heaviness in the legs when walking. In addition, patients suffering from vascular diseases of the lower limbs, such as varicose veins of the lower limbs, phlebitis of the lower limbs and other diseases, due to the poor venous return of the lower limbs, may also have the symptom of heavy walking. So in this case, first of all, we should pay attention to rest and ensure enough sleep. In addition, it is necessary to strengthen the nutrition appropriately to increase the resistance. If accompanied by other symptoms, it is also necessary to have further examination to make a clear diagnosis and carry out targeted treatment according to the cause of the disease.