Specific symptoms attributable to early hypercapnia are dyspnea (breathlessness), headache, confusion and lethargy. Abnormal heart rhythms or arrhythmias may be asymptomatic or may cause palpitations, blackouts, or breathlessness. These people have had persistent breathlessness, coughing and decreased lung function. The symptoms include fever, cough, chest pain or breathlessness. Pain may be accompanied by breathlessness, sweating, and nausea in some cases. Severe narrowings may cause chest pain (angina) or breathlessness during exercise or even at rest. She suffered from weakness, constant headaches, occasional fever, and sometimes breathlessness. This may be sufficient in treating the symptoms of swelling and breathlessness. Chest pain and sometimes mild breathlessness are the usual predominant presenting features. In 2017 Connie experienced chest pains and breathlessness. The physiological response results in temporary breathlessness and vasoconstriction. Mohan complained of stomach pain and breathlessness in the morning of 10 June 2019. High altitude oxygen was too thin for humans which induced breathlessness. Some studies suggest that oral opioids may help with breathlessness. On July 21, 1963, he was hospitalized after a severe attack of breathlessness.