Medicine can hurt as well as heal. A concrete example. Many doctors will advise you not to get a full body MRI scan. You can pretty easily buy such a service, and hire some radiologists to pour over every cubic millimetre of your body. But it's a really bad idea.
Because they will almost certainly find something ambiguous or troubling. And they're gonna biopsy. And then, well, maybe that's ambiguous. Another biopsy. You're terrified, the doctor's now worried about something they would never have known about otherwise, and maybe you have surgery to get it early. In the end the complications of all that quite potentially add up to a shorter life expectancy than simply not getting scanned in the first place. On average. Though of course, if you had a giant treatable tumour that shows up, well, you'd want the scan. But most people don't have one, and all those interventions can cause harm.
I agree in principle, but health literacy is so appallingly low - globally - that more often than not people are not equipped to deal with this information. As I said in an earlier post on this thread, look at the askdocs subreddit. 90% of the posts there are worried well asking for clarification of some unnecessary test they went and specifically asked a doctor for, the result of which they don’t understand and which is causing a cascade of health anxiety.
If every person understood enough to realise how many ‘abnormalities’ enough investigations would show up, and how in 99% of people they mean absolutely nothing, then it would be fine. But that’s not our current situation. And if you’re one of those people who are capable of parsing the dense health literature and understanding the implications (or not) of ‘normal abnormal’ findings, then go for it. But for the population as a whole? It’s not viable or helpful
Because they will almost certainly find something ambiguous or troubling. And they're gonna biopsy. And then, well, maybe that's ambiguous. Another biopsy. You're terrified, the doctor's now worried about something they would never have known about otherwise, and maybe you have surgery to get it early. In the end the complications of all that quite potentially add up to a shorter life expectancy than simply not getting scanned in the first place. On average. Though of course, if you had a giant treatable tumour that shows up, well, you'd want the scan. But most people don't have one, and all those interventions can cause harm.