Why does iron deficiency lead to headaches?
The supply of all organs in the body takes place via the transporter haemoglobin (blood pigment) in the red blood cells. If there is a pronounced iron deficiency, not enough haemoglobin can be produced. As a result, less oxygen can be bound and transported in the blood and the organs are supplied with less oxygen.
There is an oxygen deficiency (hypoxia), in this case an anaemic hypoxia. The exact mechanism of pain development is not yet fully understood. The brain reacts very sensitively to an oxygen deficiency.
Even slight fluctuations are sufficient to cause symptoms. The brain itself has no pain receptors, but the meninges (dura mater) do. It is supplied with numerous small blood vessels.
If the oxygen level in the blood drops, the vessels become narrower. To ensure sufficient blood supply to the brain, the vessels dilate immediately. This possible mechanism can explain the often pulse-like headaches.
Other accompanying symptoms
A lack of oxygen supply to the organs reactively leads to an increased heart rate and faster breathing, in order to load remaining red blood cells with oxygen faster and transport them to the organs faster. Symptoms worsen under stress because more oxygen is needed. Those affected notice a reduction in performance and constant fatigue.
Due to a lack of red blood pigment, the skin and mucous membranes appear pale. A lack of oxygen makes itself felt in the muscles in the form of twitches. This can lead to seizures, dizziness and loss of consciousness.
. Dizziness can occur in various ways. Dizziness due to iron deficiency is again caused by a lack of oxygen.
On the one hand, various areas of the brain are undersupplied, on the other hand, the organ of balance in the inner ear as well as the visual apparatus and depth perception via muscle and joint receptors are affected. The interaction of these three organs is particularly important for orientation in space. If the transmission of information is disturbed, dizziness occurs.
The exact origin of migraine is not yet fully understood. A temporary vasoconstriction with subsequent vasodilatation in the brain is partly responsible for the development of pain. This can be caused by a lack of oxygen, as is the case with iron deficiency.
The vasodilating effect can also explain the pulsatile pain character. Temporary circulatory disturbances can also lead to aura symptoms such as flashes of light. You can find more information about migraine here.
The diagnosis
A mere determination of the iron content in the blood is not sufficient to determine a state of iron deficiency. As long as the iron stores are still full, the iron content in the blood can be kept relatively constant. If iron deficiency is suspected, the ferritin value must also be determined, which is therefore lower in the case of iron deficiency (<15ng/ml for women, <30ng/ml for men).
The additionally determinable transfer insaturation is also lowered (<20%). In the case of a symptomatic iron deficiency, not enough red blood cells can be produced and the haemoglobin value is then also lowered (<12 g/dl in women, <13 g/dl in men). This topic might also be of interest to you: Iron deficiency in vegetarians
