Given that equilibrium is the desired outcome of medical herbalism, this is a balance model from which to diagnose and treat.
In the Hot/Cold model, it is considered that imbalance is in either a 'hot' or'cold' condition. This is important because, for example, a headache may be rooted in either condition, which means the treatment will differ. This is contrary to the view that every headache responds to the same treatment.
First, the features of someone in a Hot condition. Hot condtions are characterised by over-activity. These are of the circulatory system, the digestive and waste system, cardiac features, and metabolism. When diagnosing, look for colour. For example, redness in the skin or, typically, under the fingernails, indicate Hot condition. People in Hot condition seek out cold things, like cold water, cool environments, less clothing and cool compress - like in a hot condition headache, eg migraine. Patients are overactive, nervous, or fidgety, maybe thrashing about in bed. They have sensations of heat and burning and may have a raised temperature. Headache will be relieved by COLD compress.
Hot conditions require cooling herbs in order to prevent escalation of symptoms like perspiration, pain (spasm), digestive overactivity. In other words, to halt excess from the system.
Hyperthyroidism is an example of overactivity on a cellular level. Anxiety dmonstrates overactivy manifesting mentally.
In good health, we experience some hot condition upon exertion (rapid pulse, feeling flushed etc) but here our bodies nturally regain balance. In a Hot condition, we use cooling herbs (eg chammomile; feverfew) to restore balance when the body is not managing alone. That is, assisting the body in it's own recovery.
In Cold condition we see 'loss of flow'. 'Flow' can be expressed as 'chi', 'vitality', or metabolism. For example, a sluggish metabolic condition would be a cold one because of the feature of slowing down. One would seek to stimulating the flow with warming herbs- like cayenne or cinnamon - to restore equilibrium. Of course, if no improvement is seen, I would refer a patient to an orthodox medical practioner. These treatment are NOT intended to replace orthodox medical treatment, but to work alongside it.
Problems with blood efficiency are seen in COLD condition, - key words are sluggishness and inefficient activity. Also, stiffening and pain in the joints, - arthalgia or even arthritis.
In nature, everything slows down, even to dormancy, in the winter. This is a good way to view Cold condition, and not appropriate for normal health. A literal example is hypothermia, which can result in death.
Symptoms that indicate Cold condition are pale skin, or with blueish or grey tones, congestion, catarrh, stagnation in digestive system, fatigue, signs of circulation problems in the hands, painful joints, and of course, feeling cold. Always observe the behaviour of the patient too, and listen to speech as that can be indicative.
Some illnesses exhibit both Hot and Cold condition. For example, the common cold is a cold condition, but features a fever. With experience a judgement can be made about the root condition, and whether or not to include Tonics in the treatment.