Vaginal discharge can be normal for women, and can change throughout the menstrual cycle. But if becomes worse than ever before, turns an unusual dark color, or begins to itch or hurt, then it’s certainly not normal. So we call it “Vaginitis,” usually meaning infection (sometimes just inflammation) of the vagina.
Vaginitis may be due to sexual transmitted diseases (STDs, asterisks * below), but usually isn’t. The following diseases / conditions are what we think of and look for:
- Yeast (Candida; so also called “candidiasis”)
- Bacterial Vaginosis
- Trichomonas *
- Chlamydia *
- Gonorrhea *
- Herpes * (doesn’t cause discharge, rather uncomfortable or painful sores)
- Foreign body (lost tampon, etc.)
- Allergies / Irritants
- Post-Menopausal Atrophy (Atrophic Vaginitis)
- Fistulas & other rare conditions
The top three are by far the most common causes. We’d think of STDs (*) if the woman had a recent new sex partner, especially if the man didn’t use condoms (or if she suspects her regular partner had a new partner on the side).
Diagnosis is best made by pelvic exam; managing without one is possible but clearly inferior. Tests can often be obtained via the urine, or self-collected by the woman herself (we’ll discuss this below). We can see the following findings during the pelvic:
- Type of discharge — thick white sticky discharge looking like cottage cheese suggests Yeast; the discharge from Bacterial Vaginosis profuse & somewhat darkish (not clear or pure white)
- Inflamed cervix (Cervicitis) suggests Chlamydia, Gonorrhea, or Mycoplasma)
- Sores (esp. Herpes)
- Tampon that was forgotten, sex toys, other foreign bodies
- Fistulas (rare; may be hard to find), advanced Cancer (rare), other abnormalities
Since each condition above requires a different treatment, it’s crucial to know diagnosis. The tests we do are:
- Microscopic Saline Prep: Look under microscope for Trichomonas (live ones move around), “clue cells” (see below), white blood cells
- Microscopic Prep with Potassium Hydroxide (KOH): Look under microscope for Yeast
- Whiff Test of KOH Preparation above: Fishy odor from KOH on discharge suggests Bacterial Vaginosis
- pH Strip of discharge: rule out Bacterial Vaginosis by pH >4.5
- Culture for Yeast
- Swabs of discharge (each ordered, billed, & sent separately) for: Trichomonas, Bacterial Vaginosis, Gonorrhea & Chlamydia (last two may be combined)
- Swab from cervix for Mycoplasma (mainly if we see an inflamed cervicitis on pelvic exam)
We use the information obtained to make a diagnosis (see Main Topic for more brevity):
1. Bacterial Vaginosis (“BV”). Requires 3 of the following 4 criteria for diagnosis:
- Significant discharge that’s somewhat darkish (not clear or pure white)
- pH ≥5
- Positive Whiff Test — fishy odor noted when drop of KOH is added to discharge
- Clue Cells seen by microscope — normal vaginal epithelial cells with their edges completely covered by tiny bacteria (>20% of cells should look like this)
The discharge from BV isn’t itchy or burning. If these are prominent symptoms, another condition (or more than one conditions) should be suspected.
If no microscope is available to check for clue cells, we can diagnosis BV if the first three criteria above are positive. A woman can collect her own specimen for the Whiff Test & pH (the latter not as accurate as when collected by pelvic exam). In terms of type of discharge, it’s more accurate for the clinician to evaluate it by pelvic than for the patient herself.
There’s a rapid test available for the most common bacteria that causes BV, which takes 10 minutes or 1 hour (depending on the brand). These can be very useful if no microscope is available.
2. Trichomonas (“Trich”). Easily diagnosed with 100% certainty if the parasites themselves can be seen flitting around under the microscope on a saline wet prep. If none are noticed, a rapid swab test can be performed that takes 10 minutes but may miss 10% to 15% of cases. The best test has to be sent out to a regular lab and takes a day or more for results.
3. Yeast infections (Candida) are itchy or burning. They can be diagnosed by adding a drop of KOH to the discharge & then finding yeast under a microscope. If the test is negative, diagnosis can be made by culture, which takes several days, and can be false-positive in 10% to 20% of women. If the pH of the discharge is ≥5, Yeast is unlikely.
Experts recommend against empiric treatment (meaning based on a best-guess). They say it misses other diagnoses, and incurs unnecessary costs when wrong. However, 50% of women with Yeast have negative KOH tests. And treatment is easy. If the vaginal pH is 4 or 4.5, and there’s actual irritation of the vagina or labia, many clinicians including myself simply treat.
4. Chlamydia and Gonorrhea. We’d certainly look for these in a woman having unprotected sex with a new partner. The test can be collected from the urine or by pelvic exam, has to be sent out to a regular laboratory, and takes 2-3 days.
If there are no white cells in the discharge, and no irritation of the cervix when examined on pelvic exam, these conditions would be unlikely. On the other hand, if we see an inflamed cervix, we’d certainly treat for these conditions even without knowing for sure, since we wouldn’t want the bacteria to move up to the Fallopian tubes and cause Pelvic Inflammatory Disease (PID) (see Diagram: Female Genital System).
If a woman tests positive for Gonorrhea or Chlamydia, it doesn’t mean that she just got them from a recent partner. The bacteria can be present for a long time without causing any symptoms. This is important in terms of accusations of infidelity.
5. Mycoplasma genitalium. This is a recently-discovered STD for which there is no reliable test available outside of special centers. If a woman has cervicitis (as seen on pelvic exam, and confirmed by seeing scores of white blood cells under the microscope), and is negative for gonorrhea and chlamydia, we might treat for M. genitalium. Best treatment isn’t well-defined (see link to topic).
6. Herpes simplex virus (HSV). HSV doesn’t cause discharge, but rather uncomfortable or painful sores. That can easily be described as vaginal irritation. Diagnosis is suspected by noting the sores during pelvic exam; it may be necessary to have a patient point exactly to where she feels discomfort. HSV begins as a cluster of blisters, that then becomes ulcers (sores), & finally crust over.
HSV can begin at any time, but diagnosis is more certain if there’s a history of similar sores that last a few days, disappear on their own, & then recur. However, we never make the diagnosis without obtaining a specimen by swab & sending it for a test. There are lots of false-negatives if we collect the specimen after the first or maybe second day. So we may tell the patient she “may well have Herpes,” but if symptoms return, she should be seen on the first day.
There have been divorces over mistaken Herpes diagnosis. Blood tests can’t tell anything about a specific sore, and are often mistaken in general in terms of genital HSV. See our link to the topic.
7. Foreign Body. Various objects inside the vagina, like a forgotten tampon, can cause a discharge. That might sound like a strange thing to happen, but it’s not rare. Diagnosis is easily made by finding something during pelvic exam.
8. Allergies / Irritants. Various perfumes, deodorants, douches, lubricants, pads, etc. can cause vaginal irritation, though not so much a frank discharge. So can medications for vaginal infections, especially if overused (like for wrong diagnoses). We suspect this as the cause if, a) we don’t find anything else (all tests are negative); and b) we get a history of having used such products. We have the patient stop using them. If symptoms resolve, and she decides to try them again, recurrence of symptoms clinches the diagnosis.
9. Post-Menopausal Atrophy (Atrophic Vaginitis). After menopause, the loss of estrogen hormone weakens the vaginal area and causes dryness. Irritation easily develops. Diagnosis is made by the presence of menopause, typical appearance of the vaginal and genital area during pelvic exam, and absence of other diseases. At the beginning of menopause, finding a high vaginal pH >5.5, and certain post-menopausal vaginal cells on a saline prep, can be helpful. Measuring estrogen levels isn’t useful unless the results are extremely low.
10. Fistulas & other rare conditions. A fistula is an abnormal tract or passageway that develops from one organ to another (where it’s not supposed to connect). If the fistula connects the vagina with the urinary tract, there may be leakage of urine into the vagina. A fistula from anus or rectum to the vagina causes foul-smelling discharge due to leakage of feces.
Fistulas occur from gynecologic surgery, radiation, or difficult childbirth deliveries. They are rare in the U.S., but a major problem for women from poor countries. Organizations that perform fistula repairs in underdeveloped countries provide an enormously beneficial service.
A tiny fistula may be difficult to identify on pelvic exam. If the history is suggestive, and no other cause of vaginal discharge is found, women are referred to gynecologist specialists. Specialized equipment may be necessary, sometimes while introducing dye.
A variety of uncommon skin and vaginal conditions can cause irritation and discomfort. Some may be cancer or precancerous. If noted, they are diagnosed by biopsy.
Addressing Vaginal Discharge / Irritation If There’s No Microscope Available
Diagnose Yeast if: Itching, thick white cottage-cheese-like discharge on pelvic exam, pH 4-4.5. Especially think yeast if patient took antibiotics in the past 1-2 weeks, or if diabetic.
Diagnose BV if: profuse thin dark-white / light tan discharge on pelvic exam, pH ≥5, positive Whiff test when adding KOH to discharge. No itching or burning. Do rapid test if available.
Diagnose Trich if: Itching. pH ≥5. Can do rapid test if available. Send-out test takes 1-2 days.
If recent unprotected sex with new partner, send tests for Gonorrhea & Chlamydia. If cervicitis noted on pelvic exam, also send these tests, and give single dose azithromycin (treats Chlamydia & usually Mycoplasma genitalium). If one of these is found by test, a better treatment may be necessary, certainly if symptoms persist.
See also Vaginal Discharge for the clinician’s condensed thought-process when face-to-face with a patient.