Ovarian cysts are common, fluid-filled sacs that develop on or in an ovary, often forming as a natural part of the menstrual cycle in women of reproductive age. While many cysts are small, harmless, and resolve without notice, they can sometimes grow large enough to cause symptoms. The answer to whether an ovarian cyst can cause lower back pain is yes, and this discomfort is a frequent symptom reported by patients. Understanding this connection, along with other related symptoms, is the first step toward determining the cause of the pain and seeking appropriate care.
How Cysts Cause Lower Back Pain
The lower back pain associated with an ovarian cyst typically results from a mechanical effect, specifically the cyst’s size and physical location within the pelvic cavity. As a cyst grows, it occupies space and exerts pressure on nearby anatomical structures. The pain is usually described as a constant, dull ache or a feeling of heaviness, distinguishing it from the sharp, acute pain of a complication.
If the cyst is situated posteriorly, it can press directly against the nerves and connective tissues lining the back of the pelvis. This physical contact transmits discomfort into the lower back, sometimes radiating to the upper thigh or flank area. Cysts exceeding a few centimeters in diameter are more likely to create this mass effect and cause noticeable symptoms.
The phenomenon of referred pain also plays a role in back discomfort. Pain signals originating from pelvic organs, such as the ovary, travel along pathways that converge with nerves from the lower back area. The brain can misinterpret these signals, leading to the perception of pain in the lower back, even though the primary source of irritation is the cyst.
Associated Symptoms to Watch For
Lower back pain is rarely the only symptom when a cyst is large enough to cause discomfort; it is often accompanied by other localized signs within the pelvic region. Many women experience a feeling of pressure or fullness in the lower abdomen, often more pronounced on the side where the cyst is located. This sensation results from the cyst’s size pushing against the abdominal wall.
Localized pressure can also affect neighboring organs, leading to changes in bladder and bowel function. A large cyst may press on the bladder, causing a frequent or urgent need to urinate. Alternatively, it can press on the bowel, resulting in difficulty with complete emptying or constipation.
Cysts can also cause pain during sexual intercourse, known as dyspareunia, due to physical movement and pressure exerted on the pelvic organs. Furthermore, some functional cysts can disrupt hormonal balance. This disruption may lead to changes in the menstrual cycle, such as unusually heavy or lighter bleeding, or spotting between periods.
Recognizing Acute Complications
While many ovarian cysts are benign and eventually resolve, two specific complications require immediate medical attention due to the sudden onset of severe pain. Ovarian torsion occurs when the weight of a cyst causes the ovary to twist around its ligaments, cutting off its blood supply. This event typically triggers abrupt, sharp, and excruciating pain in the lower abdomen or pelvis, which may radiate to the back.
The pain from torsion is often accompanied by severe nausea and vomiting. A cyst rupture, where the fluid-filled sac bursts, is the second acute complication. A ruptured cyst also causes sudden, sharp pain in the lower back and abdomen, though intensity varies depending on the cyst’s size and whether it bleeds.
If a rupture causes significant internal bleeding, or if torsion compromises blood flow, signs of shock may develop, including lightheadedness, dizziness, or rapid heart rate. Any experience of sudden, severe pelvic pain, especially when paired with fever, vomiting, or circulatory distress, warrants an immediate emergency room visit.
Diagnosis and Management
If symptoms suggest the presence of an ovarian cyst, a healthcare provider will begin the diagnostic process with a physical examination, including a pelvic exam. During this exam, the provider may feel swelling or tenderness on one side of the pelvis. The primary imaging tool used to confirm the diagnosis is a pelvic ultrasound.
The ultrasound creates an image of the cyst, allowing the provider to determine its size, location, and composition (fluid-filled, solid, or mixed). This information classifies the cyst and guides management. Additional tests, like blood work, may be ordered to rule out other conditions or assess for specific tumor markers if the cyst has concerning features.
For many functional cysts, the recommended approach is watchful waiting, as these benign growths usually disappear on their own within a few menstrual cycles. Follow-up ultrasounds monitor the cyst’s size and appearance. If a cyst is large, persistent, or causes significant symptoms like continuous back pain, hormonal contraceptives may be prescribed to prevent new cysts from forming. Surgical removal (cystectomy) may be necessary if the cyst is very large, appears suspicious, or does not resolve, often performed using minimally invasive laparoscopic techniques.