Noticing swelling on only one side of the labia, known as unilateral labial swelling, can be alarming. This symptom is common and has several possible underlying causes. While this article provides general information, it is not a substitute for a professional medical diagnosis. The causes are often treatable, but a healthcare provider must properly evaluate the symptom to ensure appropriate care.
Bartholin’s Gland Issues
The most frequent cause of swelling confined to one side of the labia is an issue with the Bartholin’s glands. These two small glands are situated on either side of the vaginal opening. Their role is to secrete fluid through tiny ducts to lubricate the vulva.
A Bartholin’s cyst forms when the opening of one duct becomes blocked, often due to inflammation, infection, or localized trauma. When the duct is obstructed, the lubricating fluid accumulates within the gland, causing it to swell into a usually painless, fluid-filled mass. This cyst can range in size from a small pea to a large marble, often causing a noticeable lump on one side.
The cyst can become infected, leading to a painful condition called a Bartholin’s gland abscess. An abscess occurs when bacteria, such as E. coli or organisms associated with sexually transmitted infections, multiply within the trapped fluid. Unlike a cyst, an abscess typically presents with intense, throbbing pain, making walking, sitting, or intercourse difficult.
The infected gland and surrounding tissue will appear red and feel warm due to the inflammatory response. This painful, firm, pus-filled lump indicates that a simple blockage has progressed to a localized infection requiring medical attention.
Other Causes of Unilateral Labial Swelling
Swelling limited to one side can also result from localized processes unrelated to the Bartholin’s glands. Localized skin infections are a common culprit. Folliculitis is the inflammation or infection of a single hair follicle. Cellulitis, a bacterial infection of the skin and underlying tissues, can also be confined to one side, causing redness, warmth, and tenderness.
Physical injury or excessive friction is another mechanism that can cause immediate swelling. This may occur from prolonged sexual activity without adequate lubrication, friction against tight clothing, or impact from activities like cycling. The mechanical stress causes localized tissue trauma and inflammation, resulting in temporary, one-sided swelling.
Vulvar varicosities, which are varicose veins in the vulva, can also present as soft, compressible swelling on one side. These veins become enlarged and distended, often due to increased pressure and blood volume, a condition particularly noticeable during pregnancy. While usually asymptomatic, they can cause discomfort or a feeling of heaviness.
Contact dermatitis can sometimes present asymmetrically. If an irritant, like a specific soap, laundry detergent, or condom material, contacts one side of the labia more than the other, it can trigger a localized allergic or irritant response. This reaction leads to inflammation, which may include swelling, itching, and redness confined primarily to the contact area.
Immediate Steps and Medical Consultation
When unilateral labial swelling is noticed, certain self-care measures can be taken while monitoring the symptom. Applying a clean, cool compress to the affected area can help reduce inflammation and provide temporary relief from discomfort. Gentle cleansing with plain water and avoiding harsh soaps, scented products, or restrictive clothing will help prevent further irritation.
It is important to avoid any attempt to drain or squeeze the swollen area, especially if a lump or cyst is present, as this can worsen an infection or spread bacteria. If the swelling does not begin to improve within two to three days of self-care, or if it is associated with severe pain, a medical consultation is necessary. A healthcare professional can determine the exact cause and recommend targeted treatment.
Certain symptoms serve as immediate red flags that require urgent medical attention:
- Sudden onset of high fever or chills.
- Rapidly spreading redness.
- Swelling that is so painful it prevents walking or sitting comfortably.
During a medical consultation, a doctor will perform a physical examination and may take a culture of any discharge or fluid to identify a potential bacterial cause, guiding the treatment plan.