What Is Edema -How and Why Does It Occur?

Edema is the collection of fluid in the interstitial spaces or serous cavities. It becomes evident only when 5-6 liters of fluid has accumulated in the water depots.

Pitting on pressure occurs when the circumference of the limb is increased by 10%.

Mechanism : One or more of the following factors may be responsible.

• Increased capillary permeability when it is damaged e.g. acute inflammation.
• Increased capillary pressure e.g. cardiac failure.
• Decreased osmotic pressure of the blood e.g. hypoproteinemia.
• Damaged lymphatic drainage e.g. filariasis.

Site

Venous edema commonly occurs in the lower limbs which are most dependent. However, if the patient is recumbent (i.e. lies on his back), edema may be present only over the sacral region which is, then, most dependent. Lymphatic edema may occur in either limbs or over scrotum depending upon the site of involvement.

Causes

Bilateral Edema:

1. Cardiac: CCF, LVF, pericarditis
2. Renal: Acute nephritis, nephrosis
3. Hepatic: Cirrhosis of liver, portal hypertension
4. Venous: Inferior vena cava obstruction
5. Endocrine: Myxedema
6. Allergic: Angionurotic edema
7. Nutritional: Anemia, hypoproteinemia, beriberi.
8. Toxic: Epidemic dropsy

Unilateral:

A. Lymphatic:

1. Filarial
2. Pressure by new growth, metastasis
3. Radiation

B. Traumatic: Bruises, sprains, fractures
C. Infections: Cellulitis, boils, carbuncle
D. Metabolic: Gout
E. Venous: Venous thrombosis, varicose vains.
F. Hereditary: Milroy’s disease

Possible Causes of Pain in the Loin

1. Renal:
   • Stone
   • Malignancy
   • Infections (pyelonephritis, perinephric abscess, etc.)
   • Polycystic kidney
   • Dietl’s crisis-A sudden attack of acute lumbar and abdominal pain accompanied by nausea and vomiting, caused by kinking of the ureter in persons with wandering kidney.
2. Extra-renal:
   • Acute pancreatitis
   • Cholecystitis
   • Appendicitis
   • Porphyria
   • Ruptured duodenal ulcer or spleen
   • Ectopic gestation

Causes of Blood in Urine or Hematuria

Blood in urine is called hematuria in medical language. Hematuria can be due to local causes in genito urinary system or due to systemic (Involving body in general) diseases.

Blood in urine could be due to many diseases. Here is the list

• Renal:
  • Glomerulonephritis
  • Renal infarction
  • Stones
  • Tumors
  • Tuberculosis
  • Interstitial nephritis
  • Papillary necrosis
  • Polycystic kidneys
• Ureteric:
  • Trauma
  • Tuberculosis
  • Stones
  • Neoplasms
• Bladder
  • Trauma,
  • Tuberculosis
  • Stones
  • Neoplasms
  • Cystitis
  • Following cyclophosphamide therapy

• Urethral

• • Trauma
  • Stones
  • Foreign body
  • Urethritis

• Prostatic
  • Prostitis
  • Neoplasms.
• Systemic disease
  • Diabetes
  • Amyloidosis
  • Collagen disease
  • DIC

Causes of Increased Volume of Urine or Polyuria

Passage of large volumes of urine is known as polyuria. It could be caused by following

• Excessive drinking
• Diuretic therapy
• Cold weather
• Stress
• Diabetes insipidus
• Compulsive water drinking
• Diabetes mellitus
• Chronic renal failure
• Recovery from acute tubular necrosis
• Prostate Hypertrophy
• Prostate Cancer

Pyuria or Pus In The Urine-What Could Be The Causes?

Normally there are no pus cells in the urine. If there is a pus in the urine it is a cause for worry. Pus in the urine could indicate one of the following causes.

Renal:

• Infective: Pyelonephritis, pyonephrosis, perianal abscess, renal tuberculosis
• Non-infective: Hypersensitivity nephritis, analgesic nephropathy, hypokalemia, nephrocalcinosis, lead poisoning, radiation nephritis

Lower urinary tract:

• Cystitis: Infective, radiation, cytotoxic drugs.
• Urethritis.

Adnexa:

• Perinephric abscess, gynecological infections