Gallbladder disease (e.g., cholecystitis or cholelithiasis): This is the most common cause of right upper quadrant (RUQ) tenderness. The absence of fever and jaundice does not rule out gallbladder disease, as these symptoms can be variable.

Peptic ulcer disease: Ulcers in the duodenum or stomach can cause RUQ tenderness, especially if they penetrate or perforate.
Hepatitis: Although jaundice is often present, early or mild cases of hepatitis might not have jaundice, and RUQ tenderness can be a prominent symptom.
Right lower lobe pneumonia: Referred pain from the right lower lobe of the lung can cause RUQ tenderness, especially if the diaphragm is irritated.
Musculoskeletal issues (e.g., costochondritis or muscle strain): These can cause localized pain and tenderness in the RUQ area.

Appendicitis (especially if the appendix is retrocecal): Although appendicitis typically presents with right lower quadrant pain, a retrocecal appendix can cause RUQ pain.
Hepatic abscess or tumor: These conditions can cause significant morbidity if not diagnosed promptly.
Cholangitis: Infection of the bile ducts, which can be life-threatening if not treated promptly.
Pulmonary embolism: Can cause sudden onset of RUQ pain if the embolism involves the lung's upper segments.

Fitz-Hugh-Curtis syndrome: A rare condition where pelvic inflammatory disease causes adhesions between the liver and abdominal wall, leading to RUQ pain.
Intra-abdominal shunt or dialysis catheter infection: In patients with these devices, infection can cause RUQ tenderness.
Right adrenal gland pathology (e.g., hemorrhage or tumor): Rarely, diseases of the right adrenal gland can cause RUQ pain.
Intestinal obstruction or volvulus: Although these conditions often present with more diffuse abdominal pain, they can occasionally cause localized RUQ tenderness.