What could be making me so exhausted?

 | Mail Online

Dr Scurr says... This is a remarkable story of prompt diagnosis after what must have been quite a frightening incident — a tribute to your doctors.

I hope that after starting the injections of vitamin B12 you are now feeling better and the fatigue and breathlessness have eased.

Pernicious anaemia is an autoimmune
disease, meaning the body for some reason attacks itself — in this case, the stomach lining. The upshot of this is vitamin B12-deficiency.

In order to absorb this vitamin (found in meat, fish, eggs and dairy products) the body needs a substance called intrinsic factor.

This is secreted by the stomach lining and binds with the vitamin, enabling it to be absorbed; in pernicious
anaemia this intrinsic factor is no longer produced.

Other causes of a vitamin B deficiency
include a vegan diet and disorders of the small intestine such as Crohn’s disease, an inflammatory bowel disease where the damaged gut can no longer absorb nutrients.

Vitamin B12 is essential for the formation of red blood cells, so when your levels drop, your body relies on stores of B12 in the liver (the main warehouse for vitamins and nutrients). However, these run out after about three years.

This leads to a type of anaemia where the red blood cells are extra large but have a low haemoglobin content (the red pigment that attracts and carries oxygen).

And this affects the blood’s ability to carry oxygen throughout the body, causing
the symptoms you know well — breathlessness and feeling generally weak — as well as loss of appetite, constipation and abdominal pain.

Two symptoms — depression and irritability — can occur before all others, even progressing to delirium and confusion in some patients. For this reason, it should be routine to measure vitamin B12 levels in the blood in all patients presenting with acute psychiatric illness: the brain is particularly sensitive to falling levels of B12.

A B12 deficiency can also damage the nerves, so as time progresses there can be symptoms such as weakness or muscle spasms, abnormal reflexes and poor gait.

As the condition progresses fairly slowly, I hope you did not get this far — though it may have had some influence on your fall in the bathroom and your inability to get up.

Unfortunately the loss of your stomach lining’s ability to make intrinsic factor is permanent. Treatment therefore consists of a lifelong series of injections of vitamin B12 into the bloodstream, monthly at first to build up stores and then four times every year; this will be under the care of your GP and the injections can be given by the practice nurse.

There are no side-effects or dangers to this; you’re merely replacing an essential
substance you lack.

Taking additional B12 supplements or increasing the intake of foods that contain the vitamin won’t help, as the intrinsic factor needed to aid its absorption has been lost.

With the injections, your red cells will be entirely normal and your nerve cells, if damaged, will also gradually recover. This means that your health should be slowly improving and will continue to do so — better times are ahead.