Hormones affect pain tolerance. But it’s a complicated picture some people with chronic UTI feel better, some feel worse during their period. Often before a period sufferers feel a flare up of symptoms.

There appears to be no set pattern to hormone symptoms in those with UTI but some people experience an increase in swelling, pressure, pain, and frequency when oestrogen levels are highest. Others however feel better when their oestrogen levels are high.

To add to the complicated picture, another group feel best and experience less symptoms during their period, when hormone levels are low. Others experience bladder pain during their periods.

Where sufferers can agree is that almost all complain of increased ‘flare’ symptoms a few days prior to the onset of their period. The lower oestrogen levels and higher progesterone levels make people more susceptible to bladder symptoms around this time. High levels of progesterone can cause frequent urination as progesterone acts like a diuretic. The sacral nerve which controls the pelvis and its organs is full of oestrogen receptors. Research published in The International Urogynecology Journal in 1993 showed a change in hormone levels, in particular that of progesterone, may affect the excitability of the nerves and make you feel like you have to urinate more frequently.

We explain the menstrual cycle below. You may want to consider keeping a monthly note of when you experience “flares” and see if it correlates to your cycle.

How the menstrual cycle works

The first day of your period is day one of the menstrual cycle. Although both oestrogen and progesterone are at their lowest levels on day one, oestrogen begins to rise and continues to rise after menstruation.

The rise in oestrogen levels thickens the uterus in preparation for fertilisation. The rise in oestrogen also thickens the bladder lining during this time. Oestrogen levels reach their peak at ovulation, around day 14 of your cycle.

During the first two weeks of the menstrual cycle only a small amount of progesterone is present. However, after the egg is released during ovulation, oestrogen levels quickly decline and progesterone levels begin to rise in preparation for pregnancy.

Although oestrogen levels also begin to rise again, they stay at a lower level than that of the first half of the menstrual cycle. During this second half of the menstrual cycle, oestrogen and progesterone levels reach a peak around the same time, about the third week of the menstrual cycle. If the egg released during ovulation has been fertilised the progesterone levels remain high. If the egg has not been fertilised both oestrogen and progesterone production drops quickly. The decline of progesterone levels causes shedding of the endometrium (the uterine lining), which begins a new menstrual cycle.

Find out about different types of contraception and UTI.