A sacral cyst is not a tumor, but a hydatid lesion in the sacral canal. Most patients are asymptomatic, but those who have symptoms can cause pain in the area innervated by the nerve roots because sacral canal cysts often compress the sacral nerve roots, mainly manifesting as pain in the lower back, pain in the buttocks, pain in the tailbone and sacrum, pain in the perineum and external genitalia, pain in the pelvic area, pain in the groin area, and pain in the lateral hip joint. In addition the lower extremities, i.e. the lateral posterior aspect of the thighs and calves, as well as the feet, are the areas where the sacral nerve roots are distributed and pain may also occur. In addition to pain, sacral cysts also cause local sensory abnormalities, including numbness, coldness and fever in the perineum, legs and feet, etc. They can also cause muscle spasms in the legs, involuntary twitching of the toes and anal sphincter, difficulty walking, and even neurogenic claudication. Some patients may also develop rectal and anal dysfunction, which manifests as constipation, stool urgency, fecal incontinence, and anal pain. Sexual dysfunction may also occur, such as impotence and penile pain and painful intercourse in male patients; female patients may develop persistent sexual arousal syndrome, mainly manifested as repeated orgasms without any sexual stimulation. The symptoms of sacral cysts are widely distributed, which often cause clinical omission and misdiagnosis, and some patients may be treated in urology, obstetrics and gynecology, anorectology and other departments for a long time. For patients with these symptoms, if the effect is not satisfactory after a period of treatment, they should promptly undergo magnetic resonance examination of the lumbosacral spine to clarify whether they have sacral duct cysts. Once the diagnosis is clear, one should promptly go to neurosurgery to receive drug or surgical treatment to make the symptoms improve and restore health as soon as possible.