Excess aeration within the urine stream, sometimes described as bubbles or foam, can be a warning sign of more serious medical conditions such as proteinuria, an indication of conjugated bilirubin within the urine or a side effect from the medication pyridium, according to the website of pathologist Dr. Ed Friedlander. However, bubbles can also form naturally as a healthy individual expels urine.
Proteinuria is an abundance of protein within an individual's urine and is often a sign of kidney disease, explains WebMD. As normal kidney functions filter most proteins from the urine, the deterioration of a failing kidney can lead to excess proteins, such as albumin leaking into the urine from the bloodstream. It is important to note, however, that kidney failure often shows no signs in the early stages, and a doctor typically discovers kidney failure through a routine urine test during a physical exam.
Bilirubin is a brownish yellow substance produced when the liver breaks down red blood cells, notes WebMD. Conjugated bilirubin is the water soluble form of the substance, created in the liver from its unconjugated state. A doctor can perform a bilirubin test through a blood sample to measure the amount of bilirubin present within a patient's body.