The term "alexithymia" was coined by Sifneos. It is characterised by a lack of words to express emotion (a: absence of; lexi: words; thymia: emotions, affects). Its characteristics were suggested to occur more frequently in individuals with so-called "psychosomatic disorders", but this is still a matter of controversy. Here we review the psychosomatic network of alexithymia, i.e. the immune and physiological correlates of alexithymia. Some studies suggest that inaccuracy in recognising emotional states, or the way of coping with negative emotions, may influence immune function. Alexithymia is associated with higher tonic baseline levels of sympathetic activity and lower sympathetic reactivity during acute stress. Few studies have reported a diminished immune-mediated cellular response in alexithymics with oversecretion of glucocorticoids. We hypothesise that alexithymic subjects may suffer from unnoticed chronic stress with physiological and endocrine and immune consequences. Alexithymia may skew the Th-1/Th-2 balance toward Th-2 dominant immunity and lower cell-mediated (Th-1) immune response and may increase an individual's risk for stress-related disorder.