'internal illness' is correct and can be used in written English.
You could use it to refer to an illness or condition that is not clearly visible and is affecting the internal organs or systems in the body. For example, "She has been suffering with an internal illness for the past few months."
Given everything that Chamberlain has gone through in recent years — disappointments and demotions in the bullpen, an arrest for driving while impaired, time missed to arm injuries, internal illnesses — and given how close he was getting to pitching competitively again, Girardi said he wanted to check on his psyche when he spoke to him.
Their contribution is valuable purely because of their personal experience: "a living knowledge of their long-term conditions" and "the unpredictable nature of their illness" (internal report, 2008).
Locus of control measures the patient's belief in their ability to control their illness (internal locus of control) as opposed to a belief that their illness is outside their own control and primarily in the hands of others (external locus of control) or that control is a matter of luck (chance locus of control).
The Empirical sect of Sceptical inspiration, in fact, was neither concerned to study the anatomical structure of the human body nor the internal secrets of illnesses.
In some cases, the pathogen can invade the blood stream and internal organs, causing severe illness and even death.
'Abd al-Latif holds that the above sects are far removed from the medicine practiced by the Dogmatic doctors of Platonic and Aristotelian inspiration who considered anatomy and physiology to be the basic sciences and for whom the detailed study of the internal causes of an illness was primary and necessary.
The dispositional theory of evil is the one most commonly embraced by religion (original sin), medicine (internal disease), psychiatry (mental illness), and the law (personal culpability), whereas the situational theory of evil is more conventionally invoked by social psychologists, sociologists, and anthropologists sensitive to the diversity and power of environments to shape human behavior.
Although external circumstances were the source defining the category "nagging darkness", some of the informants also ascribed their illness to internal factors, such as hormones, genes or heredity.
Among patients with a chronic illness good internal consistency (alpha =.83 -.90) and test-retest reliability (r =.71) were reported previously [ 47, 48].
