health and risk factor

• Health - state of physical and mental well being
• communicable diseases - transferred between organisms
• non-communicable diseases - can't be transferred between organisms
• immune would response to antigen
• antigen is the protein found on the surface of a pathogen
• pathogens are microorganism that cause disease
• vaccine contains weakened or dead virus/bacteria, which stimulates immune system without causing illness
• poor physical health could lead to poor mental health
• substance such as carcinogens are risk factors
• lifestyle (diet, exercise, alcohol) are risk factors
• benign tumour is non cancerous, doesn't spread
• Benign tumour could grow large quickly (life-threatening if pressure/damage to an organ)
• Benign tumour is growths of abnormal cells - contained in one area (usually within a membrane)
• malignant tumours can invade other tissues or organs
• Malignant tumours can metastasise (spread through the bloodstream)
• cancer cell has mutations that allow it to divide uncontrollably
• Cancer cells have no control over their division so they keep dividing until they form a mass called a tumour.
• cancer is malignant tumour that has grown into surrounding tissue
• metastasis is when cancer cells break away from original site and form new tumours elsewhere
• malignant tumour is cancerous and it spread around body by invading healthy tissues
• metastasis - when cancer cells detach and form secondary tumours in other parts of the body 
• chemotherapy - drug that stop cancer cells self dividing
• radiotherapy - target radiation at cancer
• smoking - damages blood vessel, fatty deposits
• high fat diet - high cholesterol
• lack of exercise - obesity
• obesity - diabetes type 2
• high salt diet - higher blood pressure
• obesity + lack of exercise, lower sensitivity to insulin (control blood glucose levels), diabetes
• stress - hormones narrow blood vessels, higher blood pressure
• liver - break down alcohol, cell damaged -> scar tissue, cirrhosis of the liver
• alcohol cause brain loss of volume
• fetus - fetal alcohol syndrome (facial deformities, problems with major organs)