The menopause and your blood

Your ovaries respond less well to the signal from the pituitary gland. Fewer ovulations take place and oestrogen production becomes irregular. The pituitary compensates by raising its signal, which is why FSH moves upwards.

The years in which this happens are called the perimenopause. The menopause itself is your final period, and you can only establish that in hindsight: once your periods have been absent for twelve months.

The complaints in this phase are erratic, precisely because your hormones do not fade gradually but first become unpredictable.

In practice the menopause is established from your age, your complaints and the pattern of your cycle. A blood result supports that picture rather than settling it.

That is because of the fluctuations: a measurement taken today can look very different two weeks later. One result is therefore rarely the whole story.

Testing is mainly valuable where there is doubt: with complaints below the age of forty, with a cycle that stops without a clear reason, or when your complaints could just as easily have another cause.

In this life stage these values mainly come up:

• FSH: moves upwards as the ovaries respond less
• Oestradiol: fluctuates strongly during the perimenopause and falls afterwards
• LH and progesterone: complete the cycle picture
• Prolactin: can be another explanation for absent periods
• TSH: the thyroid causes complaints that closely resemble the menopause

If you still menstruate, preferably have blood drawn on day 3 to 5 of your cycle. If you use hormonal contraception, always mention it: you are then mainly measuring the effect of the medication.

A number of conditions produce almost the same pattern of complaints and are readily measurable:

• an underactive or overactive thyroid
• anaemia or low iron stores with heavy periods
• a deficiency of vitamin B12 or vitamin D
• a raised blood sugar, which can cause fatigue and night-time urination
• prolonged overload, sleep apnoea or low mood

If such a cause is found, something can be done about it. If nothing is found, you know that too, and it makes the conversation with your GP about your menopausal complaints more focused.

Once the menopause is behind you, the question changes. The loss of oestrogen is associated with a less favourable cholesterol profile and with bone loss in the longer term.

Valuable tests are then more likely to be a cholesterol profile, glucose and HbA1c, vitamin D and calcium, and thyroid function.

Contact your GP with heavy periods that make you anaemic, with bleeding between periods, and always with bleeding after your periods have been absent for twelve months or longer.