The concept of Imtila (plethora) is defined vividly and scientifically in Unani classical literature. Imtila (plethora) is the most common humoral disease and has multiple etiology and clinical manifestations. The signs and symptoms associated with Imtila (plethora) are headaches, clogged eyes, pulsatile conduits, flushing of the face, puffiness of the face, inability to speak, heavy head and dark and dense urine, etc. Long-lasting effects of untreated Imtila (plethora) can lead to various co-morbidities, such as Jarayan al-Dam (Haemorrhage), Tashannuj (Convulsion), Sakta (Apoplexy), Falij (Paralysis), Junun (Insanity) Hidhayan (Delirium), Ghashi Imtila’i (Syncope), Ufunat-e-dam (infection in the blood), Dasoomat e Dum (dyslipidemia), etc. Therefore, it is essential to identify the symptoms of Imtila (plethora). Early detection will aid in obtaining urgent medical attention and treatment, which can reduce complications. Unani physicians used various methods to eliminate surplus, harmful, and undigested humour that might have further tainted the humour. Unani physicians prescribed various exercises and regimens in combination with food and drugs to restore the humoral balance of the body. The present review paper systematically emphasizes the proper understanding of Imtila (plethora) to understand its etiopathogenesis, signs, & symptoms, and complications. We have also discussed the course of treatment suggested by Unani physicians considering the physiopathology and clinical characteristics.