Several studies have shown increased frequencies of other symptoms in patients with idiopathic hypersomnia, although it is not clear whether these symptoms are caused by the idiopathic hypersomnia.[10][16] These symptoms include palpitations, digestive problems, difficulty with body temperature regulation, and cognitive problems, especially deficits in memory, attention, and concentration.[16] Anxiety and depression are often increased in idiopathic hypersomnia, most likely as a response to chronic illness.[10] Peripheral vascular symptoms, such as cold hands and feet (Raynaud’s-type phenomena) have been noted in some patients. In addition to difficulty with temperature regulation and Raynaud’s type symptoms, other symptoms associated with autonomic dysfunction were also noted. These included: fainting episodes (syncope); dizziness upon arising (orthostatic hypotension); and headaches (possibly migrainous in quality).[16] Food cravings and impotence have also been reported.[17] These are subjective symptoms reported by only a small number of patients.