Kegel exercises work your pelvic floor muscles, and can help with both urinary incontinence and sexual dysfunction. They may even make childbirth easier, reducing the risk of tearing during delivery, according to Open Door Midwifery. It's extremely unlikely that you'll injure yourself doing these exercises, but you can still overdo them to the point of mild to moderate pain.
If you isolate the wrong muscles when doing Kegels, you can increase your risk of injury. For example, you might inadvertently tense your back or your stomach, leading to back pain. Instead, isolate your pubococcygeus muscles by urinating, then stopping the flow mid-stream. Use this same motion when doing Kegels. Begin with five to 10 reps, held for three to five seconds. Work up to holding your Kegels for 30 seconds or so. Do three to five sets of five to 10 reps per day. If this is too much and leads to discomfort, reduce the number of reps.
Emptying the Bladder
If your bladder is full when you're doing your Kegel exercises, you'll get a lower-quality workout and could even cause urinary leakage. It's important to empty your bladder fully prior to doing Kegels, and to avoid the exercise if you feel any pain or tingling in your bladder. If bladder pain continues, consult your doctor.
According to the University of Maryland Medical Center, there's no benefit in doing excessive Kegel repetitions. Rather than focusing on increasing the number of Kegels you do, try to hold each rep longer. You can gradually build to more reps after you're easily holding a rep for 10 seconds or longer. If you feel pain in your abs while doing Kegels, it's likely that you're either targeting the wrong muscles or you've done so many reps that your abs are now compensating for weaknesses in your PC muscles.
The biggest risk of overdoing Kegels is temporary muscle pain, often in the vagina or around the rectum. It's extremely unlikely that you'll tear or otherwise severely injure your PC muscles, but if you experience pain, burning or stretching, take a break from Kegels until the pain goes away. If the pain gets worse or is severe, avoid Kegels and call your doctor.