Can people with a cold or cough take Rehmannia glutinosa (Shu Di Huang)?

Generally speaking, people with cough caused by wind-cold common cold are not advised to take prepared rehmannia (Shu Di Huang). However, individuals whose cough is caused by wind-heat common cold or yin deficiency of the lungs and kidneys may take prepared rehmannia under the guidance of a physician. Detailed explanations are as follows:

Prepared rehmannia is slightly warm in nature and has nourishing properties. Patients with wind-cold common cold may experience increased internal cold pathogens after taking it, which could worsen their condition or prolong the illness. Patients with wind-cold common cold are advised to take medications that dispel wind-cold and relieve exterior syndromes, such as ephedra and cinnamon twig. Prepared rehmannia has the effect of nourishing yin and clearing heat, and may help alleviate symptoms such as cough and yellow phlegm caused by wind-heat common cold or yin deficiency of the lungs and kidneys. However, it should be used under the guidance of a physician to avoid excessive or improper use.

Prepared rehmannia has a sticky and rich texture that is not easily digested. Its use by individuals with weak spleen and stomach functions (those with spleen and stomach weakness) may worsen symptoms such as abdominal distension and abdominal pain. People allergic to any component of prepared rehmannia should avoid taking it. It is recommended that treatment be administered under a physician's guidance, including symptomatic treatments such as cough suppression, phlegm removal, antiviral or antibacterial therapy, and nebulization therapy. In addition, patients should rest adequately, maintain good indoor air circulation, drink plenty of water, follow a light and easily digestible diet, and consume more foods rich in vitamin C and protein to enhance immune function and promote recovery.