Probably, it is difficult to find the person at whom face skin would not redden from time to time. It can occur for very many reasons: beginning from psychological state and finishing with any serious diseases.
The person can redden because has got into awkward situation or has got agitated. For example, he for some reason is ashamed, confusion, or is forced to communicate with people with whom obviously does not sympathize, or he should answer unpleasant questions, to listen to unfair criticism, etc. As bodies of blood system are controlled vegetative (autonomous) nervous system, irrespective of desires of the person, he cannot influence change of diameters of capillaries. And capillaries in the above cases extend, blood flows to the surface of skin, and the person reddens.
Rush of blood to face skin can be also for other household reasons, for example, from tiresome physical activity, from overheating, including after bath, hot shower. Overheating from direct sunshine ("sunstroke") also leads to reddening of face skin.
Sometimes it is caused by allergic reactions to some components of cosmetics, perfumery. Also women in the period of climax have reddening of skin ("inflows") – the most everyday and inevitable occurrence. However reddening can be also symptom of diseases. For example, temperature increase, especially is higher than 38.5 - 39 degrees, practically is always followed by redness of the person. There is also very unpleasant disease with the beautiful name – rozatseya. Its main signs - constantly reddening nose and face. Can serve as provocative factor, anything, beginning from increase (or lowerings) air temperatures, finishing with intake of hot food or alcoholic beverages. In the hard, started cases, the face of the patient is disfigured: the nose becomes unnaturally big, swelled up, skin becomes covered by ugly hillocks, large time, vascular "asterisks". At this stage except therapeutic treatment, often it is necessary to resort to the help of the plastic surgeon. At some especially impressionable, irritable people the face skin very often and strongly reddens, even when for this purpose, it seems, there is no reason. It can be symptom of neurosis therefore it is desirable for such people to address for consultation the qualified doctor-neuropathologist.