ed in liver tissue and causes yellow discoloration. The sonographic appearance of stone is characterized by its echogenicity, focal shape and produces sharp acoustic shadowing. A study done by Verna et al.  had studied the aetiological spectrum of obstructive jaundice; they reported that malignant obstructive was more common than benign (62.73% vs. 47.27%), carcinoma of the head of pancreas was the commonest aetiology (33.63%) followed by choledocholiathiasis (29%). They concluded that carcinoma of head of pancreas and choledocholithiais were the commonest malignant and benign etiology respectively. In present study, gall stones are more common in females than males (61.33% vs. 27.33%). The masses represent the common cause of obstructive jaundice. In this study, abdominal masses are the second cause (32.67%) of obstructive jaundice. In this study, these masses are not differentiated as benign and malignant; this needs biopsy and histopathological analysis which have been taken after ultrasound investigation. This result agrees with a study done by Iqbal et al.  who reported that 32% of the causes of obstructive jaundice were Ca-head of pancreas. In literature, tumours causing biliary channel obstruction are generally ampullary carcinomas, gall bladder carcinomas extending into the CBD, metastatic tumours (usually from the gastrointestinal tract or the breast), secondary lymphadenopathies at the portahepatis and cholangio carcinomas  . In our study, abdominal masses are observed in females more than males (27.33 vs. 5.33 respectively). In previous studies, the disease is more common in men than women   though the difference in rates has narrowed over recent decades, probably reflecting earlier increases in female smoking. In the United States the risk for African Americans is over 50% greater than for whites, but the rates in Africa and East Asia are much lower than those in North America or Europe. The United States, Central and Eastern Europe, Argentina and Uruguay all have high rates  .
The present study has identified the main symptoms of the obstructive jaundice. It is observed that vomiting, yellow discoloration and abdominal pain are the most common symptoms. In literature, the signs and symptoms of obstructive jaundice differ depending on the completeness of the blockage, and the disease course varies among individuals. Some people with obstructive jaundice may have no symptoms initially, but if the condition persists, they may have severe abdominal pain, fever, nausea, and vomiting. Complete blockage may also occur, posing a risk of infection leading to liver and gallbladder damage  .
Ultrasound plays a great role in detecting and evaluating obstructive jaundice and it should be the first line of investigation. The main causes of obstructive jaundice are biliary stones and carcinoma of the head of pancreas respectively. Gender and age show significant difference with the causes of obstructive jaundice.