Psychology
ADHD in children: signs, diagnosis and treatment
ADHD is more than an active child. What the signs are, what else can look like it, how it is assessed, and which treatments help at each age.
27 Sept 20269 min read
Differential diagnosis
Also known as Differentials, The list of possibilities
A differential diagnosis is the list of conditions that could explain a person's symptoms, ranked by likelihood and by danger. It is how a doctor thinks before a diagnosis is reached, and the reason questions and tests follow the order they do.
Symptoms are not diseases. A cough, a headache or pain in the upper abdomen is a starting point that a dozen different conditions can produce, and the work of a consultation is to narrow that field. The list a clinician holds in mind is the differential, and it is ordered on two axes at once: what is most likely given this person's age, history and circumstances, and what would be most dangerous to miss even if it is unlikely.
Why it matters to you
Understanding the differential explains a great deal of what happens in an appointment. Questions that seem irrelevant — about travel, about a relative's illness, about weight over the past six months — are usually there to strike an item off the list or move it up. A test is ordered to separate two possibilities rather than to survey everything, which is why more tests are not automatically better care: a test with no candidate diagnosis behind it produces incidental findings that lead to more tests.
- Say when it started, and what has changed since. Time course narrows the list faster than the description of the itself.
- Mention the frightening thing you are privately worried about. It may already be on the list and can be addressed directly; if it is not, saying so lets it be put there or ruled out.
- Bring every medicine, including herbal and over-the-counter ones. A is on almost every differential and is the easiest item to confirm.
- Ask what else it could be, and what would change the plan. It is a reasonable question and a good doctor has an answer ready.
Sometimes the list cannot be narrowed to one on the day, and the honest plan is to treat the most likely cause and review — with clear instructions about what should prompt an earlier return. Safety-netting of that kind is not indecision. It is how uncertainty is managed responsibly when the alternative would be investigating everyone for everything.
Where this comes up
Psychology
When the mind causes physical symptoms: psychosomatic and functional symptoms
Pain, dizziness or even seizures can come from how the nervous system is working rather than from damage. The symptoms are real, and they can be treated.
27 Sept 20268 min read
Gastroenterology
Irritable Bowel Syndrome: When the Gut Hurts but the Tests Are Normal
IBS is a real disorder of how the gut and brain communicate, not nerves or imagination. Diagnosis is positive rather than a process of exclusion, and several treatments work.
19 Aug 20269 min read
Related terms
- SymptomA symptom is something a patient notices and reports — pain, nausea, tiredness. It differs from a sign, which is something a doctor can observe or measure.
- PrognosisOutlookA prognosis is the expected course of a condition — how it is likely to develop and what the chances of recovery are. It is a statement about probability across many people, not a prediction about one.
- ScreeningScreening testScreening is testing people who feel well, to find a condition earlier than symptoms would. It is only worth doing when finding the condition early genuinely changes what happens next.
- BiopsyTissue sampling, Histopathology sampleA biopsy is the removal of a small piece of tissue so that it can be examined under a microscope. It is the test that settles what a lump, an ulcer or an abnormal patch actually is, when scans and blood tests can only suggest.