Dr Mureithi is a Senior Consultant Pulmonologist in Nairobi, specialising in respiratory tract allergies, autoimmune allergies, adult internal medicine, and adult chest and respiratory diseases. He has admission rights to Nairobi Hospital, Mater Hospital, Karen Hospital, and Nairobi South Hospital, treating chest conditions including asthma, COPD, TB, bronchitis, lung cancer, and pulmonary hypertension. Dr Mureithi is the Founder and Chairman of the National Asthma Association of Kenya, an organisation supporting three specialised asthma clinics: Kiambu Hospital, Kangundo Hospital, and Muranga Hospital.