Not medical advice: There are many factors that could be causing you to feel like you have to pee, but not being able to do so.
Prostate enlargement, infection, surgery, constipation, certain medications, bladder stones, urethral stricture, pelvic injury, and stroke. Urinary retention is a symptom of all of these health issues.
Urinary retention is when you have an urge to urinate, but cannot do so. This particular condition is more common in men than it is in women, and does need medical treatment. When you are experiencing urinary retention, it may be caused by a blockage in the urethra, or a disruption of the nerve system that is connected to the urinary tract. The signals that are needing to be sent to your brain and your nervous system may not be in sync with one another. An enlarged prostate in a man can be the main cause. A disruption of the nerve system could be caused by what is called a "neurogenic bladder." This is the main cause for incontinence in the urinary system.
Other symptoms of neurogenic bladder include: wetting oneself involuntarily, or having dribble in which the bladder isn't fully emptied. You should see a doctor for this to determine the exact cause of the bladder problems. A lot of people with Multiple Sclerosis experience these types of issues.
You could also be experiencing a Urinary Tract Infection, which is something else you would need to contact your doctor for. Symptoms of a UTI do include problems with the bladder, such as a persistent urge to urinate, as well as passing small amounts of urine.
The FDA recently discovered that the wrinkle treatment Botox can treat an overactive bladder! They found that if injected into the bladder muscle, it can help the bladder muscle relax, which will then reduce urinary incontinence. Very interesting information!