Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL



Urea and Electrolytes (U&E) is a common blood test to assess kidney function and electrolyte balance.

U&E typically includes sodium, potassium, urea, creatinine and eGFR.



Ulcerative colitis (UC) is a form of IBD, which causes inflammation of the colon and rectum.



ULN means 'upper limit of normal'.


USA and US refers to the United States (of America).

NB: for ultrasound, see USS.


An ultrasound scan, or ultrasound (USS) uses ultrasonography: non-ionising, high-frequency sound waves to characterise tissue.

USS is used for diagnosis and investigation (including in pregnant women, obstetric ultrasound) and to guide intervention (such as USS-guided FNA).

PoCUS is a specific example of USS.

NB: To avoid confusion, USS is used in place of US, which refers to the United States (of America).

Radiopaedia - Ultrasound


Urinary tract infection (UTI) is an infection in any part of the urinary system. Lower UTI affects the bladder (cystitis); upper UTI affects the ureters or kidneys (pyelonephritis).

UTI is more common in females.

Complicated UTI occurs when the urinary tract is abnormal, if a patient has a catheter (catheter-associated UTI), if the causative organisms are atypical, or if there are predisposing co-morbidities such as poorly controlled diabetes. Uncomplicated UTI is caused by typical organisms in people with a normal urinary tract and kidney function. Complicated UTI increases risk of persistent infection, treatment failure and recurrent infection (recurrent UTI).

Most UTIs can be easily treated with antibiotics, although recurrence is possible, particularly in women.

NICE CKS - Lower UTI in women

NICE CKS - Lower UTI in men

NICE CKS - Pyelonephritis (acute)

NICE CKS - UTI in children