Increasing access to, and use of, genome profiling may provide opportunity for diagnosis based on presentation and genetic risk factors, by identifying ApoL1 gene variants on chromosome 22.

The definitive diagnosis of HN requires morphological examination. Common histological features can be identified in the renal and glomerular vasculature. Glomerulosclerosis is often present, either focally or globally, which is characterized by hardening of the vessel walls. Also, luminal narrowing or the arteries and arterioles of the kidney system. However, this type of procedure is likely to be preceded with a provisional diagnosis based on laboratory investigations.

Guidelines for referral to a nephrologist vary between countries. Though most would agree that nephrology referral is required by Stage 4 CKD (when eGFR/1.73m is less than 30 ml/min; or decreasing by more than 3 ml/min/year); and may be useful at an earlier stage (e.g. CKD3) when urine albumin-to-creatinine ratio is more than 30 mg/mmol, when blood pressure is difficult to control, or when hematuria or other findings suggest either a primarily glomerular disorder or secondary disease amenable to specific treatment. Other benefits of early nephrology referral include proper patient education regarding options for renal replacement therapy as well as pre-emptive transplantation, and timely workup and placement of an arteriovenous fistula in those patients opting for future hemodialysis

Screening those who have neither symptoms nor risk factors for CKD is not recommended. Those who should be screened include: those with hypertension or history of cardiovascular disease, those with diabetes or marked obesity, those aged > 60 years, subjects with indigenous racial origin, those with a history of kidney disease in the past and subjects who have relatives who had kidney disease requiring dialysis. Screening should include calculation of estimated GFR from the serum creatinine level, and measurement of urine albumin-to-creatinine ratio (ACR) in a first-morning urine specimen (this reflects the amount of a protein called albumin in the urine), as well as a urine dipstick screen for hematuria. The GFR (glomerular filtration rate) is derived from the serum creatinine and is proportional to 1/creatinine, i.e. it is a reciprocal relationship (the higher the creatinine, the lower the GFR). It reflects one aspect of kidney function: how efficiently the glomeruli (filtering units) work. But as they make up <5% of the mass of the kidney, the GFR does not indicate all aspects of kidney health and function. This can be done by combining the GFR level with the clinical assessment of the patient (especially fluid state) and measuring the levels of hemoglobin, potassium, phosphate and parathyroid hormone (PTH). Normal GFR is 90-120 mLs/min. The units of creatinine vary from country to country.

Usually, the diagnosis of ADPKD is initially performed by renal imaging using ultrasound, CT scan, or MRI. However, molecular diagnostics can be necessary in the following situations: 1- when a definite diagnosis is required in young individuals, such as a potential living related donor in an affected family with equivocal imaging data; 2- in patients with a negative family history of ADPKD, because of potential phenotypic overlap with several other kidney cystic diseases; 3- in families affected by early-onset polycystic kidney disease, since in this cases hypomorphic alleles and/or oligogenic inheritance can be involved; and 4- in patients requesting genetic counseling, especially in couples wishing a pre-implantation genetic diagnosis.

The findings of large echogenic kidneys without distinct macroscopic cysts in an infant/child at 50% risk for ADPKD are diagnostic. In the absence of a family history of ADPKD, the presence of bilateral renal enlargement and cysts, with or without the presence of hepatic cysts, and the absence of other manifestations suggestive of a different renal cystic disease provide presumptive, but not definite, evidence for the diagnosis. In some cases, intracranial aneurysms can be an associated sign of ADPKD, and screening can be recommended for patients with a family history of intracranial aneurysm.

Molecular genetic testing by linkage analysis or direct mutation screening is clinically available; however, genetic heterogeneity is a significant complication to molecular genetic testing. Sometimes a relatively large number of affected family members need to be tested in order to establish which one of the two possible genes is responsible within each family. The large size and complexity of PKD1 and PKD2 genes, as well as marked allelic heterogeneity, present obstacles to molecular testing by direct DNA analysis. The sensitivity of testing is nearly 100% for all patients with ADPKD who are age 30 years or older and for younger patients with PKD1 mutations; these criteria are only 67% sensitive for patients with PKD2 mutations who are younger than age 30 years.

The standard diagnostic workup of suspected kidney disease is history & examination, as well as a urine test strip. Also, renal ultrasonography is essential in the diagnosis and management of kidney-related diseases.

The diagnosis of medullary cystic kidney disease can be done via a physical exam. Further tests/exams are as follows:

- A routine blood test called the serum creatinine can be done. Creatinine is a breakdown product from the muscle, as kidney function declines, the amount of blood creatinine goes up. Thus, most affected individuals have no symptoms of MCKD, but find that they have the condition due to an elevation in the blood creatinine level.

- Affected individuals also have an elevation in the blood uric acid level. In MCKD, the kidney has difficulty getting rid of uric acid. One can find out that the uric acid level in the blood is high when a blood test is done. Gout is caused by high uric acid levels, and thus patients often have gout.

- A kidney ultrasound in this condition usually shows normal or small sized kidneys (occasionally cysts are present). However, since cysts are present in many normal individuals, these cysts are not helpful in making a diagnosis, therefore a kidney biopsy can be done to determine if the individual has this disease. Kidney biopsy is a procedure where a needle is inserted into the kidney and removes a small piece of kidney tissue. This tissue is then examined under a microscope.

- Definitive testing and diagnosis of MCKD can be made by analyzing the UMOD gene for mutations, this can be done by a blood test.

In ADPKD patients, gradual cyst development and expansion result in kidney enlargement, and during the course of the disease, glomerular filtration rate (GFR) remains normal for decades before kidney function starts to progressively deteriorate, making early prediction of renal outcome difficult. The CRISP study, mentioned in the treatment section above, contributed to build a strong rationale supporting the prognostic value of total kidney volume (TKV) in ADPKD; TKV (evaluated by MRI) increases steadily and a higher rate of kidney enlargement correlated with accelerated decline of GFR, while patient height-adjusted TKV (HtTKV) ≥600 ml/m predicts the development of stage 3 chronic kidney disease within 8 years.

Besides TKV and HtTKV, the estimated glomerular filtration rate (eGFR) has also been tentatively used to predict the progression of ADPKD. After the analysis of CT or MRI scans of 590 patients with ADPKD treated at the Mayo Translational Polycystic Kidney Disease Center, Irazabal and colleagues developed an imaging-based classification system to predict the rate of eGFR decline in patients with ADPKD. In this prognostic method, patients are divided into five subclasses of estimated kidney growth rates according to age-specific HtTKV ranges (1A, 6.0%) as delineated in the CRISP study. The decline in eGFR over the years following initial TKV measurement is significantly different between all five patient subclasses, with those in subclass 1E having the most rapid decline.

To stage the degree of damage in this (and any) kidney disease, the serum creatinine is determined and used to calculate the estimated glomerular filtration rate (eGFR). Normal eGFR is equal to or greater than 90ml/min/1.73 m.

There is no diagnostic test for calciphylaxis. The diagnosis is a clinical one. The characteristic lesions are the ischemic skin lesions (usually with areas of skin necrosis). The necrotic skin lesions (i.e. the dying or already dead skin areas) typically appear as violaceous (dark bluish purple) lesions and/or completely black leathery lesions. They can be extensive. The suspected diagnosis can be supported by a skin biopsy. It shows arterial calcification and occlusion in the absence of vasculitis. Sometimes the bone scintigraphy can show increased tracer accumulation in the soft tissues. In certain patients, anti-nuclear antibody may play a role.

Diabetic nephropathy in type 2 diabetes can be more difficult to predict because the onset of diabetes is not usually well established. Without intervention, 20-40 percent of patients with type 2 diabetes/microalbuminuria, will evolve to macroalbuminuria.

Diabetic nephropathy is the most common cause of end-stage kidney disease, which may require hemodialysis or even kidney transplantation. It is associated with an increased risk of death in general, particularly from cardiovascular disease.

The diagnosis of nephronophthisis can be obtained via a renal ultrasound, family history and clinical history of the affected individual according to Stockman, et al.

Classically, MSK is seen as hyperdense papillae with clusters of small stones on ultrasound examination of the kidney or with an abdominal x-ray. The irregular (ectatic) collecting ducts are often seen in MSK, which are sometimes described as having a "paintbrush-like" appearance, are best seen on intravenous urography. However, IV urography has been largely replaced by contrast-enhanced, high-resolution helical CT with digital reconstruction.

In terms of treatment/management for medullary cystic kidney disease, at present there are no specific therapies for this disease, and there are no specific diets known to slow progression of the disease. However, management for the symptoms can be dealt with as follows: erythropoietin is used to treat anemia, and growth hormone is used when growth becomes an issue. Additionally, a renal transplant may be needed at some point.

Finally, foods that contain potassium and phosphate must be reduced

Millions of people across the world suffer from kidney disease. Of those millions, several thousand will eventually or do need kidney transplants. Out of those millions in the world, 16,500 in the United States needed a kidney transplant in 2008. Of those 16,500 people, 5,000 died while waiting for a transplant. Currently, there is a shortage of donors, and in 2007 there were only 64,606 kidney transplants in the world. This shortage of donors is causing countries to place monetary value on kidneys. Countries such as Iran and Singapore are eliminating their lists by paying their citizens to donate. Also, the black market accounts for 5-10 percent of transplants that occur worldwide. The act of buying an organ through the black market is illegal in the United States. To be put on the waiting list for a kidney transplant, patients must first be referred by a physician, then they must choose and contact a donor hospital. Once they choose a donor hospital, patients must then receive an evaluation to make sure they are sustainable to receive a transplant. In order to be a match for a kidney transplant, patients must match blood type and human leukocyte antigen factors with their donors. They must also have no reactions to the antibodies from the donor’s kidneys.

The microscopic examination of tissue (histology) gives the definitive diagnosis. The diagnostic histopathologic finding is intravascular cholesterol crystals, which are seen as cholesterol clefts in routinely processed tissue (embedded in paraffin wax). The cholesterol crystals may be associated with macrophages, including giant cells, and eosinophils.

The sensitivity of small core biopsies is modest, due to sampling error, as the process is often patchy. Affected organs show the characteristic histologic changes in 50-75% of the clinically diagnosed cases. Non-specific tissue findings suggestive of a cholesterol embolization include ischemic changes, necrosis and unstable-appearing complex atherosclerotic plaques (that are cholesterol-laden and have a thin fibrous cap). While biopsy findings may not be diagnostic, they have significant value, as they help exclude alternate diagnoses, e.g. vasculitis, that often cannot be made confidently based on clinical criteria.

Some forms of glomerulonephritis are diagnosed clinically, based on findings on history and examination. Other tests may include:

- Urine examination

- Blood tests investigating the cause, including FBC, inflammatory markers and special tests including (ASLO, ANCA, Anti-GBM, Complement levels, Antinuclear antibodies

- Biopsy of the kidney

- Renal ultrasonography is useful for prognostic purposes in finding signs of chronic kidney disease, which however may be caused by many other diseases than glomerulonephritis.

Tests for inflammation (C-reactive protein and the erythrocyte sedimentation rate) are typically elevated, and abnormal liver enzymes may be seen. If the kidneys are involved, tests of renal function (such as urea and creatinine) are elevated. The complete blood count may show particularly high numbers of a type of white blood cell known as "eosinophils" (more than 0.5 billion per liter); this occurs in only 60-80% of cases, so normal eosinophil counts do not rule out the diagnosis. Examination of the urine may show red blood cells (occasionally in casts as seen under the microscope) and increased levels of protein; in a third of the cases with kidney involvement, eosinophils can also be detected in the urine. If vasculitis is suspected, complement levels may be determined as reduced levels are often encountered in vasculitis; complement is a group of proteins that forms part of the innate immune system. Complement levels are frequently reduced in cholesterol embolism, limiting the use of this test in the distinction between vasculitis and cholesterol embolism.

In people with microscopic hematuria, it is important to rule out any possible confounders such as menstruation in women, possible presence of semen in sample or recent rigorous exercise. In menstruating women, tests should be repeated during non-bleeding parts of their cycles. In individuals with history of recent rigorous exercise, urinalysis should be repeated 4–6 weeks following cessation of exercise. All women of child-bearing age should undergo a pregnancy test, and if positive should receive an ultrasound of their kidneys and bladder with further invasive diagnostic work-up deferred until completion of pregnancy.

If diagnostic work-up has been unyielding so far or the aforementioned risk factors are present, it is important to begin a thorough work-up for possible malignancy especially of the bladder and kidney by referring to a Urologist to look at the urethra and bladder with a cystoscopy and also performing additional imaging using CT urography, which provides a thorough view of the complete urinary system.

For individuals with persistent hematuria with no immediate identifiable cause, urinalysis should be repeated once a year, and if it is negative for 2 years then you can stop repeating the tests. However, if it is positive for 3 years, repeat anatomic evaluation should be done.

The management of this condition can be done via-improvement of any electrolyte imbalance, as well as, hypertension and anemia treatment as the individuals condition warrants.

For people with visible hematuria and evidence of blood clots, further imaging with an abdominal CT scan should be done and an urgent referral to a urologist made. Otherwise, the next step involves determining if source of bleeding is glomerular in nature as evidenced by presence of inappropriately shaped/dysmorphic red blood cells, presence of protein in the urine, new or worsening hypertension or swelling. If source is glomerular patients should be referred to a nephrologist for further evaluation. Non-glomerular source of bleeding will usually require further work-up by a urologist.

Unfortunately, response to treatment is not guaranteed. Also, the necrotic skin areas may get infected, and this then may lead to sepsis (i.e. infection of blood with bacteria; sepsis can be life-threatening) in some patients. Overall, the clinical prognosis remains poor.

Based on studies conducted in the United States, the prognosis for individuals with ALECT2 amyloidosis is guarded, particularly because they are elderly and their kidney disease is usually well-advanced at the time of presentation. End-stage renal disease develops in 1 out of 3 patients and has a median renal survival of 62 months. A suggested prognostic tool is to track creatinine levels in ALect2 patients. The attached Figure gives survival plotss for individuals with LECT2 renal amyloidosis and serum creatinine levels less than 2 mg/100 ml versus 2 mg/100 ml or greater than 2 mg/100 ml. The results show that afflicted individuals with lower creatinine levels have a ~four-fold higher survival rate.

It can be difficult to make a Vascular disease diagnosis since there are a variety of symptoms that a person can have, also family history and a physical examination are important. The physical exam may be different depending on the type of vascular disease. In the case of a peripheral vascular disease the physical exam consists in checking the blood flow in the legs.

In the general population, the frequency of medullary sponge kidney disease is reported to be 0.02–0.005%; that is, 1 in 5000 to 1 in 20,000. The frequency of medullary sponge kidney has been reported by various authors to be 1221% in patients with kidney stones. The disease is bilateral in 70% of cases.