Luckily for us, many below-the-belt issues aren’t super serious. That sour-y smell? Meh, vaginas can smell like that. Some pain during sex? Don’t panic—it’s pretty common, and may be only temporary. 

But there are certain gynecological symptoms that require attention ASAP. Wondering if your issue falls into the take-care-of-this-stat category? There are two major things to consider, says Michael Krychman, MD, director of The Southern California Center for Sexual Health and Survivorship in Newport Beach, California: The severity of the pain, and how quickly it developed.

Below are four symptoms you should get checked out sooner rather than later.

It “burns” when you pee, and your discharge looks ... different

Some vaginal discharge is totally normal—but if you notice a significant difference in its color, odor, or consistency, that could be a red flag. “Women are used to their own cycle,” Dr. Krychman says, “so when that starts changing, it’s an indication that something could be wrong.”

Dr. Krychman also points out that it’s hard to self-diagnose what’s causing abnormal discharge: “More often than not, [people make the wrong] assessment,” he says. “They try and treat it themselves, and wind up with an infection.” A few possible culprits include a yeast infection, bacterial vaginosis (an overgrowth of normal vaginal bacteria), or chlamydia—a sexually-transmitted bacterial infection, and the most commonly reported infectious disease in the United States. Chlamydia should be treated right away because the infection can spread to your uterus, ovaries, and fallopian tubes within a few days or weeks, causing pelvic inflammatory disease and possibly infertility.

RELATED: 7 Sneaky Reasons Your Vagina Itches

Your vagina is swollen and really itchy

These symptoms could be triggered by anything from a bubble bath, to menopause, to a yeast infection. And often times, it’s no big deal. On the other hand, you might have trichomoniasis, an STD that’s caused by a parasite. That sounds scary, but according to the U.S. Centers for Disease Control and Prevention, it’s “the most common curable STD.” Only about 30% of people will have any symptoms, but the most common ones in women are irritation, burning, redness, and soreness.

Trichomoniasis is diagnosed with a lab test, and treated with a single dose of a prescription antibiotic. Make sure your partner gets checked out too, so you avoid re-infecting each other. Not only can trichomoniasis make sex more painful, but it can also trigger problems during pregnancy and make you more susceptible to other STDs.

You bleed after sex

Up to 9% of premenopausal women may experience post-coital bleeding (which is bleeding after sex that’s not related to their period) according to a 2014 review in the journal Obstetrics and Gynecology International. The good news is that for most women, the problem will go away within 6 months. But since post-coital bleeding is also a common symptom of both cervical cancer and vaginal cancer, your doctor might want to rule out the big C with a biopsy. Other culprits include endometriosis and benign cervical polyps.

RELATED: 10 Ways to Deal With Painful Sex

There’s a bump down there that hurts

As a general rule, you should call your ob-gyn if you can feel a lump inside (or sticking out of) your vagina. Fortunately most cysts (if that's what it is) are pretty harmless, and probably won’t even need treatment. But if you have what’s called a Bartholin cyst or abscess—a buildup of pus in the glands that flank the vaginal opening—you may develop a painful infection that could make it hard to walk or sit. Soaking in a warm bath might help you feel better, but you may also need to get the cyst drained via an in-office surgical procedure.