Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Why would my doctor test my kidney infection if my finger is mysteriously injured?27F, 165cm, 70 kg, white, smoker, drinker, in Netherlands. No drugs, prescription or otherwise.Primary complaint: The middle joint on my left pointer finger is mysteriously painful. I woke up after a normal night (i.e. no drinking, couldn't have forgotten an injury) and the middle joint of my finger hurt, as if it had been slammed in a door. The pain is localized and only experienced when I attempt to bend my finger. It began on the 11th of March.Existing issues: Ehlers Danlos Syndrome, Hashimoto Thyroidism, Anemia, Asthma, AllergiesMy primary doctor saw me today and did not think there was anything biomechanically wrong, i.e. no break, no dislocation. She tested my blood for infections as I've just returned from the tropics (Thailand) but that was negative. She then ordered a lot more blood tests, liver function, kidney function, arthritis, etc.I understand testing for arthritis, but why kidney and liver function? I am an immigrant in the Netherlands, so sometimes there is a bit of a language barrier and I don't completely understand how my finger pain could be related to kidney or liver failure.. ### Response: Could be many reasons. Kidney and liver function is good to have if you will be prescribing medication that is filtered by the kidney or liver. Your doctor may be worried about a rheumatologic or infectious disease which can also sometimes affect the liver or kidney. Also some STDs like gonorrhea can cause arthritis and can be tested for in the urine.Those are just basic labs..