Causes

Your kidneys filter waste products from your blood while retaining what your body needs � including proteins. However, some diseases and conditions allow proteins to pass through the filters of your kidneys, causing protein in urine.

Conditions that can cause a temporary rise in the levels of protein in urine, but don't necessarily indicate kidney damage, include:

• Dehydration
• Emotional stress
• Exposure to extreme cold
• Fever
• Strenuous exercise

Diseases and conditions that can cause persistently elevated levels of protein in urine, which might indicate kidney disease, include:

• Amyloidosis (buildup of abnormal proteins in your organs)
• Certain drugs, such as nonsteroidal anti-inflammatory drugs
• Chronic kidney disease
• Diabetes
• Endocarditis (an infection of the inner lining of the heart)
• Focal segmental glomerulosclerosis (FSGS)
• Glomerulonephritis (inflammation in the kidney cells that filter waste from the blood)
• Heart disease
• Heart failure
• High blood pressure (hypertension)
• Hodgkin's lymphoma (Hodgkin's disease)
• IgA nephropathy (Berger's disease) (kidney inflammation resulting from a buildup of the antibody immunoglobulin A)
• Kidney infection (pyelonephritis)
• Lupus
• Malaria
• Multiple myeloma
• Nephrotic syndrome (damage to small filtering blood vessels in the kidneys)
• Orthostatic proteinuria (urine protein level rises when in an upright position)
• Preeclampsia
• Pregnancy
• Rheumatoid arthritis (inflammatory joint disease)
• Sarcoidosis (collections of inflammatory cells in the body)
• Sickle cell anemia