Dysuria means difficulty or pain in the process of expelling urine. The amount of urine may be reduced, it may be expelled painfully or it may be ejected in small quantities each time, the sufferer left with the urge to void his bladder all the time. The three main causes of dysuria are:

(i) cystitis-inflammation of the bladder;
(ii) inflammation of the urethra;
(iii)veneral diseases like gonorrhea.

Another cause is the enlargement of the prostate gland, a structure which lies at the neck of the bladder in men and surrounds a part of the urethra lying within the pelvis. Hyper acidity may also cause dysuria in some cases because the excessive amount of acid present in the urine produces the feeling of pain in the process of its ejection from the bladder.

The main symptoms of dysuria are:

(i) scanty urine
(ii) pain in the process of urination; 
(iii) pain in the penis (and in woman, in the ovaries); 
(iv) passage of urine flecked with blood; 
(v) a feeling of heaviness in the region of the kidneys and sometimes, the scrotum; and
(vi) the ever-present urge to pass the urine.

Nocturnal polyuria occurs in both men and women. It becomes more common as people age.

Nocturnal polyuria is caused by the following:

• Congestive heart failure — A condition where the heart muscle weakens and can not pump blood efficiently throughout the body. If the heart can not pump efficiently, fluids can build up in your extremities (eg, legs). Swollen ankles are one sign of heart failure. During the night, your body absorbs this excess fluid, changing it into urine, and creating a need for you to urinate in the middle of the night.
  
  
• Hypoalbuminemia — An abnormally low blood level of albumin. Normally, albumin is the most plentiful protein in human blood and the key to the regulation of its osmotic pressure. Albumin helps blood hold on to its fluidity, so as albumin levels decrease, fluid eases out of the bloodstream and body as urine.
  
  
• Venous insufficiency — Venous insufficiency is a condition in which the flow of blood through the veins is impaired. When this happens, fluids can build up in your extremities and lead to the creation of excess urine and the need to urinate in the middle of the night.
  
  
• Excessive fluid intake  —Especially during the evening hours (i.e. after 7 p.m.). This includes all fluids from water to alcohol and caffeine in particular. Keep in mind that certain foods contain a lot of water too, such as salads, vegetables, fruits, rice and pasta.
  
  
• Use of long-acting diuretics — May result in the need for you to urinate in the middle of the night.
  
  
• Sleep apnea  — Sleep apnea is a sleep disorder in which breathing stops in intervals that may last from 10 seconds to a minute or longer. Sleep apnea triggers certain hormones in the heart that promote urine loss.
  
  
• Insomnia —  Trouble sleeping