Persistent – the longitudinal clinical record shows that, with few exceptions, the required finding(s) has been at, or is expected to be at, the level specified in the listing for a continuous period of at least 12 months

Duration - has lasted or can be expected to last for a continuous period of at least 12 months

Renal - pertaining to the kidneys

Hemodialysis or dialysis - the removal of toxic waste from the blood by filtering it through an artificial kidney machine

Peritoneal dialysis – a type of dialysis in which dialyzing solution is introduced into and removed from the peritoneal (abdominal) cavity either continuously or intermittently

Creatinine - normal product of muscle metabolism

Serum creatinine - the amount of creatinine in the blood, which measures renal function; determined by blood sample 

Creatinine clearance test - a test for renal function based on the rate at which creatinine is excreted by the kidney; determined by a blood sample and 24 hour urine sample 

Renal osteodystrophy - bone disorders usually caused by chronic kidney failure, and may result in bone pain and pathologic fractures (bone breaks due to weakening of the bone structure).

Types of renal osteodystrophy include:

• Osteitis fibrosa - fibrous degeneration with weakening and deformity of bone
• Osteomalacia - softening of bone
• Osteoporosis - thinning of bone with reduction in bone mass resulting from the depletion of calcium and bone protein

Neuropathy - a problem in peripheral nerve function (any part of the nervous system except the brain and spinal cord) that causes pain, numbness, tingling, and muscle weakness.

• Sensory neuropathy - a neuropathy or polyneuropathy (more than one nerve) involving only the sensory nerves (nerves of feeling)
• Motor neuropathy - a neuropathy or polyneuropathy (more than one nerve) involving only the motor nerves (nerves of muscle function)

Fluid overload syndrome - excessive sodium (salt) and water retention in the body that cannot be adequately removed by the diseased kidneys resulting in vascular congestion (fluid overload of blood vessels)

Signs of vascular congestion:

• Ascites - excess fluid in the abdomen
• Pleural effusions – fluid around the lungs
• Pulmonary edema – fluid inside the lungs
• Pericardial effusion – fluid surrounding the heart
• Diastolic hypertension - elevated diastolic blood pressure (the bottom number of a blood pressure reading)

Symptoms of vascular congestion include:

• Dyspnea - shortness of breath
• Fatigue
• Weakness

Glomerular diseases – diseases of the kidney that can cause chronic kidney failure; classified into two categories, nephritic and nephrotic kidney conditions.

• Nephritic conditions – associated with inflammation of the internal structures of the kidney
• Nephrotic conditions – associated with increased excretion of protein in the urine

Nephrotic syndrome - a general name for a group of diseases involving defective kidney glomeruli (filtration system) characterized by:

• Heavy proteinuria - large amount of protein in the urine
• Hypoalbuminemia – low albumin levels in the blood
• Hyperlipidemia - high fat level in the blood
• Varying degrees of edema –swelling

Anasarca - generalized massive edema (swelling) of soft tissues

Proteinuria - excess protein in the urine (most accurately measured with a 24 hour urine test)

Serum albumin - a major protein found in the blood that transports drugs and other substances, and is important for keeping fluid from leaking out of blood vessels into the tissues