We will now go through the 10 complications of CKD. We will focus on the physical complications. This article is linked to another on 10 Most Common CKD symptoms (caused by its 10 complications).
Note. These 10 complications largely only occur in more advanced CKD (CKD4-5).
The symptoms of CKD relate to the complications, but it is not a one-to-one relationship, i.e. each symptom may have 2 or more complications that cause (e.g. tiredness). And some complications have no symptoms at least initially (high blood pressure).
Note. CKD – and especially advanced CKD (Stage 4-5 CKD) – are also complicated by major mental health and social issues, which are as (or more) important that the physical ones.
AKI usually ‘gets better’. But in some patients, AKI may cause (or accelerate the progression) of CKD. Occasionally it leads to ESRF.
Symptoms: dominated by cause of AKI, e.g. pneumonia or post-cardiac surgery.
Fluid overload and hyperkalaemia are two of the main indications for dialysis.
Symptoms: fluid overload (ankle swelling, shortness of breath); hyperkalaemia (usually no symptoms).
3. High blood potassium level (hyperkalaemia)
This is usually asymptomatic, i.e found on a blood test. But if severe (>7.0 mmol/L) it can cause whole body muscle weakness.
Hypertension also accelerates the progression of CKD.
Almost all people with CKD have hypertension. High cholesterol can also be caused by nephrotic syndrome (defined by a urinary albumin:creatinine ratio (ACR) levels greater than 220 mg/mmol) with normal kidney function.
Symptoms: high blood pressure and high cholesterol are usually ‘silent’ with no symptoms (as is CKD, usually until Stage 4 CKD).
Such as ischaemic heart disease (IHD), peripheral arterial disease (PVD), chronic heart failure (CHF), and strokes (CVAs).
Symptoms: chest pain (IHD); shortness of breath (CHF); pain in legs on walking or poor circulation to feet (PVD); and one-sided weakness or speech or visual disturbance (stroke).
Renal anaemia is due to reduced production of erythropoietin (EPO) by the kidney, reduced red blood cell survival, and iron deficiency.
Treatment with EPO is recommended when haemoglobin is less than 110 g/L
Symptoms: tiredness, shortness of breath, lethargy, and palpitations.
Renal bone disease is caused by disturbed vitamin D, calcium/phosphate, and parathyroid hormone (PTH) metabolism.
Serum calcium is low initially, with vitamin D deficiency; and raised serum phosphate and parathyroid hormone levels.
Symptoms: usually no symptoms; when more severe, bone pain and weakness (and fractures eventually). When severe, it occasionally causes calciphylaxis. This is serious but fortunately rare.
Malnutrition is common in advanced CKD and ESRF, thought to be due to renal acidosis (high acid levels in the blood), poor dietary intake and hypoalbuminaemia (low protein levels in the blood).
Symptoms: can be none in early stages; later in CKD, patients lose appetite and lose weight, especially muscle weight (and power).
Symptoms: this may present with paraesthesia, sleep disturbance, and restless legs syndrome.
1 in 100 people with CKD progress to Stage 5 CKD (kidney failure, or ERSF) – i.e. fortunately this is rare. These patients will require renal replacement therapy (RRT; dialysis or kidney transplantation) or supportive care (no dialysis or transplant).
The risk of all-cause mortality significantly increases with progressive CKD.
Note. People with CKD are 5-10 times more likely to die prematurely, than they are to progress to end-stage renal failure (ESRF). The risk of death rises exponentially as renal function worsens, and is largely secondary to heart disease.
People with ESRF may have an excess cancer risk, particularly affecting the urinary tract and thyroid gland. The exact cause is not known, but risk factors may include exposure to immunosuppressive agents, and immune dysregulation caused by CKD.
Kidney transplant recipients have an overall risk of cancer about three times compared to the general population; with an overall risk for males of about double, and for females over triple.
There are significantly increased risks in both sexes of Kaposi’s sarcoma, lymphomas, leukaemias, anogenital and skin cancers. All are thought to be secondary to immunosuppression.
Here is more information on cancer risk in transplant patients: Letto, 2023.
We have described what are the 10 complications of CKD. We hope it has been helpful.
