Swelling in the genital area is common and usually points to something treatable, like an infection, irritation from a product, or a fluid-filled cyst. It can affect anyone regardless of sex, and the specific cause depends on where exactly the swelling is, how quickly it appeared, and whether you have other symptoms like pain, discharge, or fever. In most cases it resolves on its own or with simple treatment, but a few causes need prompt medical attention.
Common Causes in Women and People With Vulvas
The vulva, the outer area of the genitals, can swell for a wide range of reasons. The most frequent culprit is some form of vaginal or vulvar infection. Nearly 75% of women experience a yeast infection at least once in their lifetime, and the hallmark symptoms are swelling, itching, and a thick white discharge. Bacterial vaginosis, another common infection, can cause swelling along with a thin grayish discharge and a noticeable fishy odor.
Bartholin cysts are another possibility. These form when one of the small glands near the vaginal opening gets blocked. They can range from the size of a pea to as large as a golf ball, and small ones often cause no symptoms at all. When a cyst becomes infected and turns into an abscess, though, it swells rapidly, becomes very tender, and can make sitting or walking uncomfortable. Soaking in warm water (a sitz bath) for a few days sometimes helps a small cyst drain on its own. If it keeps growing, becomes painful, or causes a fever, a doctor can drain it with a simple procedure.
Contact dermatitis is a surprisingly frequent cause of vulvar swelling that many people overlook. The skin in this area is thinner and more sensitive than skin elsewhere on the body, so it reacts strongly to chemical irritants. Common triggers include scented soap, bubble bath, laundry detergent, dryer sheets, synthetic underwear, panty liners, douches, spermicides, and even certain types of toilet paper. Switching to fragrance-free products and wearing cotton underwear often clears things up within a few days.
Common Causes in Men and People With Testicles
Scrotal swelling has its own set of causes. Epididymitis, an inflammation of the coiled tube behind each testicle, is one of the most common. It typically develops gradually over a day or two and causes aching pain alongside swelling. In younger men it’s often linked to a sexually transmitted infection; in older men it’s more commonly caused by a urinary tract infection.
A hydrocele is a painless buildup of fluid around a testicle that makes one side of the scrotum look larger than the other. It’s usually harmless and doesn’t need treatment unless it becomes large enough to cause discomfort. A varicocele, which is an enlarged vein inside the scrotum, can also create a feeling of heaviness or a visible swelling that some people describe as looking like a “bag of worms.” Both conditions are common and typically not dangerous.
An inguinal hernia can cause swelling near the groin or in the scrotum when part of the intestine pushes through a weak spot in the abdominal wall. The telltale sign is a bulge that becomes more obvious when you stand up, cough, or strain, and tends to flatten when you lie down. It often comes with a burning or aching sensation at the site.
Sexually Transmitted Infections
Several STIs can cause genital swelling in any sex. Chlamydia and gonorrhea both cause swollen, painful testicles in men and can trigger vaginal discharge and pelvic discomfort in women. Gonorrhea in particular tends to produce a thick, cloudy, or bloody discharge. Trichomoniasis can cause irritation ranging from mild to serious inflammation, often with a greenish-yellow discharge.
Genital herpes can cause swelling during a first outbreak, typically alongside small painful blisters or sores and swollen lymph nodes in the groin. You might also feel flu-like symptoms during that initial episode, including fever, headache, and muscle aches. Syphilis can cause swollen lymph nodes as well, though its primary sign is a painless sore at the site of infection.
STI-related swelling almost always comes with at least one other symptom: unusual discharge, pain during urination, sores, or a rash. If you notice any combination of these alongside swelling, getting tested is the clearest path to the right treatment.
Swelling During Pregnancy
Genital swelling is common in pregnancy and usually harmless. Increased blood volume and pressure from the growing uterus can cause fluid to pool in the vulvar area, leading to general puffiness. Some pregnant women also develop vulvar varicosities, which are swollen veins on or around the vulva. These occur in roughly 8% to 22% of pregnancies, typically appearing after 12 weeks. If you also have varicose veins in your legs, the likelihood rises above 20%.
The good news is that these varicose veins almost always resolve on their own within about six weeks after delivery. In the meantime, pelvic compression garments or snug-fitting supportive underwear can help relieve the heaviness and discomfort. Avoiding prolonged standing and lying on your left side to reduce pressure on the major veins can also make a noticeable difference.
How to Ease Swelling at Home
For mild, non-emergency swelling, a sitz bath is one of the simplest and most effective remedies. Fill a bathtub or a plastic sitz bath basin with three to four inches of warm water, around 104°F (40°C). Soak for 15 to 20 minutes and repeat up to three or four times a day. This works well for Bartholin cysts, general irritation, and postpartum swelling.
A cold compress wrapped in a cloth can reduce swelling from an injury or allergic reaction. Over-the-counter pain relievers can help manage discomfort. If you suspect a product is causing irritation, eliminate scented soaps, detergents, and anything that contacts the area directly, then reintroduce them one at a time to identify the trigger. Wearing loose, breathable cotton underwear gives the area room to heal.
Signs That Need Immediate Attention
Most genital swelling isn’t an emergency, but a few situations require fast action. Testicular torsion, where a testicle twists and cuts off its own blood supply, causes sudden, severe pain on one side of the scrotum along with swelling, nausea, and sometimes vomiting. The testicle can only survive about six hours without blood flow. Nearly everyone keeps the testicle if treated within four to six hours, but after 24 hours, only about 10% do. Any sudden, intense testicular pain warrants an immediate trip to the emergency room, even without other symptoms.
A strangulated inguinal hernia is another emergency. If a hernia bulge suddenly becomes very painful, turns red or purple, and you can’t push it back in, or if you develop nausea, vomiting, or fever, the trapped tissue may be losing blood supply. This requires surgery to prevent serious complications.
For vulvar swelling, a rapidly growing lump with fever and worsening pain suggests an abscess that needs drainage. And in anyone over 40 who develops new, unexplained swelling or lumps in the genital area, getting evaluated promptly helps rule out less common but more serious causes.