Hidden pain in the abdomen to the left of the navel may be caused by enteritis, intestinal cramps, adnexitis, pelvic inflammatory disease, ovarian cysts, appendicitis, urethritis, stones and other diseases. 1. Enteritis. Inflammation of the left intestinal mucosa, mucosal edema, increased secretion, causing irritation to the gastrointestinal tract, resulting in left abdominal pain. 2. Intestinal cramps. The intake of allergy-inducing food, excessive gas in the gastrointestinal tract, and irritation from cold and hunger cause muscle spasm of the intestinal wall, leading to left abdominal pain. 3. Adnexitis. Poor hygiene, after intrauterine surgical operations, and decreased immunity of the body may increase the chance of infection. Inflammation of the left adnexa causes increased leukorrhea and pain in the lower back. Stimulation of coitus may cause hidden pain in the left abdomen. 4. Pelvic inflammation. Vulvovaginitis, disease-causing microorganisms retrograde infection into the pelvic cavity causing inflammation. Inflammatory secretions increase and gather in the pelvis, causing pain in the left abdomen or the whole abdomen. 5. Ovarian cysts. Ovarian follicles rupture during ovulation, and the follicular fluid flows into the pelvic cavity, causing hidden pain in the left side of the abdomen. Ovarian cysts gradually increase in size and cause irritation to the surrounding tissues, which can cause pain in the left side of the abdomen. 6. Appendicitis. Poor dietary habits, constipation and heredity are more likely to induce appendicitis. The position of the appendix may change, which can cause metastatic abdominal pain, sometimes causing hidden pain in the left lower abdomen. 7. Urethritis, stones. Inflammation of the urinary system, stones, tumors occur in the left abdomen, resulting in local hidden pain. Hidden pain in the abdomen on the left side of the navel may also be other causes, and it is recommended to consult a doctor in time, combined with the doctor’s advice for treatment.