Various signs and symptoms are observed by the physician for diagnosing the liver abscess. Those include:

• Immune system symptoms: Liver abscess induces inflammatory responses, as the body develops a defensive mechanism upon entry of a foreign organism. The immune system defends foreign bodies, which results in fever (increasing body temperature), weakness, nausea, vomiting, night sweats, abdominal pain, anorexia (loss of appetite), and weight loss. 
• Right shoulder pain: Symptoms like pain in the right shoulder can happen when a liver abscess irritates the phrenic nerve. 
• Respiratory system symptoms: The phrenic nerve regulates the diaphragm, essential for breathing. Irritation or injury to this nerve may result in respiratory dysfunction. Patients who experience respiratory dysfunction caused by compression, infection, or damage to the diaphragm may complain of symptoms like coughing, dyspnea, and orthopnea. 
• Jaundice:  Liver abscesses induce obstructive jaundice as they compress and alter the structure of the bile ducts within the liver. Pressure from this source causes the liver to overflow with bile, which causes jaundice (yellowing of the skin and eyes).
  

There are several invasive and noninvasive tests in diagnosing liver abscess. On suspicion of liver abscess based on the history and clinical presentations of a patient a health care physician advises for further diagnostic tests which includes the following.

• Blood tests
• Imaging tests

Blood tests for liver abscess diagnosis

Various laboratory tests are done to determine liver abscess. These are done by collecting samples of blood or aspirating the abscess. Tests include:

• Complete blood picture: In liver abscess patients, elevated white blood cells and a reduction in red blood cells (anemia) are observed.
• C-reactive protein: C-reactive protein, or CRP, indicates the severity of infection. It is a helpful indicator for determining how often antibiotics are used and how effective they are in treating liver abscesses. Increased CRP is observed which indicates high infection. 
• Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT): These liver enzymes can be elevated in people with abscesses, indicating liver damage. ALT was earlier called serum glutamic pyruvic transaminase (SGPT) and AST was called serum glutamic oxaloacetic transaminase (SGOT). 
• Alkaline phosphatase (ALP): Increased in people with liver abscess, indicating bile duct obstruction. 
• Gamma-glutamyl transpeptidase (GGT): Increased GGT levels may indicate liver impairment, bile duct damage, or blockage. 
• Bilirubin: Jaundice (bilirubin build-up in the blood) due to impaired liver functions and causes yellow discoloration of the skin and eyes. Elevated bilirubin levels can indicate a problem with the liver's ability to clear the waste product. 
• Hypoalbuminemia: When a person has a liver abscess, their liver's production of this albumin (protein) may be reduced, which suggests impaired liver function. Except for the hyaluronic acid test, most serum assays are indirect indicators of liver impairment. 
• International normalized ratio (INR): It is used to measure the clotting time of blood. It can also track how patients with liver abscesses respond to blood-thinning medications.
• Prolonged prothrombin time: Prothrombin time estimates blood clotting time. An increase in the duration of this test suggests impaired liver function and a potential risk of bleeding. 
• Blood cultures: Needed particularly in cases where hematogenous spread is the cause of the liver abscess.
• Aspiration culture: The culture of aspirate of liver abscesses is crucial to find the cause of liver abscess. 
  

Imaging tests for liver abscess diagnosis

The diagnosis of liver abscesses is primarily based on imaging techniques. Various imaging tests are used to diagnose liver abscesses. They are: 

Chest X-ray: This can show the fluid level in the abscess cavity, right pleural cavity, or elevation of the right diaphragm.

Ultrasonography (US): Of the abdomen is still the recommended initial imaging test. Its benefits include its widespread availability, noninvasiveness, and capacity to evaluate the liver for localized lesions, their types, and other abdominal organs to determine the infection's source. 

Computed tomography (CT): With contrast helps locate intra-abdominal abscesses. Over 90% of hepatic abscesses may be detected, and their cause is established by computed tomography.

Magnetic resonance cholangiography (MRCP): It determines the localization of bile duct obstruction.

Endoscopic retrograde cholangiopancreatography (ERCP): It enables bile duct stenting and ERCP drainage.

The clinical presentations of liver abscesses are similar to various other diseases. Differential diagnosis is categorized into two types, they are:

• Before imaging: It includes acute gastritis, bacterial pneumonia, biliary disease, acute cholecystitis, hydatid cyst, parapneumonic pleural effusions, and empyema.
• After imaging: Malignancy
  

Diagnosis done by patient’s history, physical examination, and laboratory findings comes under differential diagnosis before imaging. 

• Acute gastritis: Acute gastritis is the temporary inflammation of the stomach lining caused by stress on the gastric mucosa, mucosal barrier disruption, and infections. This condition is usually associated with prominent stomach and bowel issues that tend to resolve spontaneously within a few days. 
• Bacterial pneumonia: Pneumonia is a condition where one or both of your lungs are infected, leading to the accumulation of pus in the air sacs. The most common cause of pneumonia is bacteria. 
• Biliary disease: The biliary system is impacted by a wide range of illnesses, many of which have comparable clinical signs and symptoms.
• Acute cholecystitis: The most frequent causes of cholecystitis or gallbladder inflammation are stones within the gallbladder (gallstones) or that originate from the gallbladder and obstruct the cystic duct.
• Hydatid cysts: Humans can get hydatid disease, a parasitic infection, of which Echinococcus granulosus is the most common species. Dogs are the ultimate hosts of adult parasites, living in their stomachs. Cattle, horses, and sheep are intermediate hosts. 
• Parapneumonic pleural effusions and empyema: Pleural effusion happens when fluid builds up in the area between the tissue layers that cover the lungs and the chest cavity. Parapneumonic pleural effusion results from pneumonia and may be resolved with antibiotics, but in severe cases, it can lead to a fibrinous reaction and the presence of pus, known as empyema or empyema thoracis.
  

After imaging

Diagnosis done based on imaging tests like ultrasonography, computed tomography, and magnetic resonance imaging is considered an after-imaging diagnosis. 

• Hepatocellular Carcinoma (HCC): It is a primary liver cancer that predominantly affects people with cirrhosis and underlying chronic liver disease.

A comprehensive strategy is necessary for the treatment of a liver abscess. It focuses on managing the infection, reducing complications, and facilitating the patient's recovery since there is a significant risk of death in untreated patients. Below is a description of the factors and procedures considered by medical professionals in the treatment of liver abscesses: 

• Selection of antibiotics: Antibiotic misuse is a recognized issue, and treating liver abscesses in low-resource settings poses significant challenges with limited medical options available to doctors. 
• Patient education: Providing patients and the public with direct instructions on food and personal hygiene, including hand wash and hygiene sex practices. 
• Abscess characteristics: Lesions in the liver that take up space are called pyrogenic liver abscesses (PLA). Abscesses have varying clinical characteristics and prognoses. The physician chooses treatments based on the bacterial culture results. 
• Postoperative and rehabilitation care: The maintenance of antibiotics, monitoring blood counts, renal function, bilirubin, and aminotransferases are all part of postoperative prophylaxis. 
• Treatment options: To choose the best treatment needed according to the severity of the condition. Drainage is an important treatment pattern and can be performed under ultrasonography or computerized tomography. Needle aspiration, percutaneous drainage, laparoscopic drainage, and surgery are also performed. Antibiotics are prescribed based on clinical findings when the pathogen is unknown. 
• Microbial factor: Diagnosing the disease as a liver abscess is the primary element. Identifying the causative organism through a culture test and then treating the patient according to the organism is the next challenging factor for the physician .
• Follow up: Liver abscess can reoccur if not managed properly with antibiotics and drainage when needed. One must be careful about the comorbidities and risk factors associated with liver abscesses. Continuous follow-up with the health care professional is mandatory and monitored by the physician to prevent recurrence.
  

Managing liver abscesses requires a comprehensive approach to controlling the infection, avoiding complications, and promoting liver recovery. Following treatment and regular monitoring is important to confirm that the abscess is healing, and the liver is working properly. The objective is to achieve full recovery and reduce the risk of future issues. 

• Identifying and eliminating: Identifying the causative organism and treating it accordingly with antibiotic therapy is the treatment pattern for liver abscess. Eliminating the causative organism helps in curing the disease. 
• Symptomatic relief: Symptomatic treatment other than antibiotic therapy is also prescribed for the management of fever, pain, cough, and other associated symptoms, ensuring the patient’s comfort and recovery. 
• Prevention of complications: Untreated liver abscess is deadly. So, early detecting and treating liver abscesses can help in preventing serious complications. 
• Improving quality of life: The goal of the healthcare team in treating any disease is to improve the quality of life of the patients.