Usually, the muscles at the neck of the bladder form a tight seal to hold the urine in without leaks. If these muscles are weak or damaged, then a sudden increase in pressure may cause some urine to leak out into the urethra, which is the outlet for the bladder. This channel being highly sensitive, the entrance of some urine into it can trigger a contraction of the bladder, causing even more urine to leak out.
Stress incontinence is often caused by damage to the hammock of ligaments that supports the bladder neck. This often occurs after childbirth and is particularly associated with big babies, long labours, and deliveries involving instruments (forceps). The symptoms may not be too noticeable at first but may worsen after menopause as lack of oestrogen causes the hammock tissue to weaken.
Other factors that may contribute to this condition are obesity, and chronic diseases which induce persistent coughing, like bronchitis, and smoking-induced coughing.
Some women may have a sag in their ligaments because of a collagen deficiency. Collagen is a protein which is present in great abundance in the body, particularly in connective tissue, and provides elasticity to ligaments and tendons.
Treatment of stress incontinence involves strengthening the muscles that support the bladder neck to raise the hammock upwards. Pelvic floor exercises are helpful for many women and should be started early in life. It is important that they are done properly, and if there is any doubt or the symptoms are not improving the advice of a physiotherapist is recommended.
However, as women grow older, the benefit gained from these may reduce as tissues weaken further with age.
There is now medication available that can lead to a 50% or more improvement in the symptoms of stress incontinence. It works by increasing the tone of the muscle at the neck of the bladder.
Many women will find the above measures useful, but for those that don’t, there are various minor surgical procedures that can be performed.
The bladder is a balloon with walls made up of muscle fibres, and the muscular part of the bladder is called the detrusor. When urine fills the cavity, the muscle stretches and becomes highly strung. This creates the desire to empty and, when it is appropriate the bladder neck muscles relax, the detrusor contracts and the urine flows out. This movement is usually synchronised, however in some situations the bladder muscles become irritable and will contract at inappropriate times causing a strong urge to pass urine that may cause some urine to leak out.
The main treatments for this condition are bladder retraining and/or medication. Bladder retraining is usually done in conjunction with pelvic floor exercises by a physiotherapist or specialist nurse. There is a variety of medication available that acts by dampening down the irritability of the bladder muscle.