Step 1: Infectious Diseases.
Common infectious diseases in humans include:
1. Tuberculosis (TB): Caused by Mycobacterium tuberculosis, affecting the lungs and causing coughing and chest pain.
2. Malaria: Caused by Plasmodium parasites and transmitted through the bite of infected mosquitoes, leading to fever and chills.
3. Influenza (Flu): Caused by influenza viruses, leading to fever, fatigue, and respiratory symptoms.
Step 2: Non-Infectious Diseases.
Common non-infectious diseases include:
1. Diabetes: A metabolic disorder that affects how the body uses blood sugar.
2. Hypertension (High Blood Pressure): A condition where the force of the blood against the artery walls is too high, leading to various cardiovascular problems.
3. Cancer: A group of diseases characterized by the uncontrolled division of abnormal cells.
Step 3: Conclusion.
These diseases can be caused by a variety of factors, including infections, genetic predisposition, lifestyle choices, and environmental factors.
Final Answer:
\[
\boxed{\text{Common diseases include tuberculosis, malaria, diabetes, hypertension, and cancer.}}
\]