Symptoms can be evolved through the Symptoms screen. Evolving a symptom costs DNA points, but each evolution will make your pathogen increase infectivity, severity, or lethality.
In the standard diseases, there are 6 symptoms available immediately. The others must be evolved after you have evolved a symptom in contact with it. These initially available symptoms are Nausea, Coughing, Rash, Insomnia, Cysts, and Anaemia. The most deadly are Total Organ Failure, Hemorrhagic Shock and Necrosis. The most infective are Skin Lesions, Necrosis and Dysentery next to Insanity, Systemic Infection, and Diarrhoea tying at 6 infectivity increase.
Certain symptoms will create symptom combos, which generally increase disease effectiveness, but also increase awareness of the disease. Some combos increase research speed while others decrease it. They are not reversible; once they evolve they remain in effect even if you devolve the symptoms that triggered them. You will get achievements for every symptom combo you trigger.
The below table lists the base symptom costs for each symptom. Unless you have enabled the Sympto-Stasis gene, each symptom evolved from the six initially available will have an additional point added. For example, if you are evolving symptoms that cost 2, 5, 12, and 19, when you get to the symptom that costs 5, it will be six, when you finally get to the symptom that costs 19, it will now be 22. To get to Total Organ Failure from Coughing, which is the cheapest way, it will cost 47 DNA points. It costs a total of 779 DNA points to evolve all 32 symptoms (283 with Sympto-Stasis), so it is impossible to evolve all symptoms without Sympto-Stasis, mutations or the Unlimited Strain cheat.
| Name | Info | DNA | Infectivity | Severity | Lethality | Cure Requirement |
|---|---|---|---|---|---|---|
| Nausea | Irritated stomach lining leads to discomfort. Slight chance of infection when kissing | 2 | 1 | 1 | 0 | 0.01 |
| Coughing | Chance of infection by spreading pathogen into surroundings, especially in high density, urban areas | 4 | 3(0.05 urban effectiveness) | 1 | 0 | 0.01 |
| Rash | The skin becomes blistered and painful, slightly increasing infectivity | 3 | 2 | 1 | 0 | 0.01 |
| Insomnia | Inability to sleep makes people irritable and less productive | 2 | 0 | 3 | 0 | 0.03 |
| Cysts | Painful lumps containing pockets of the pathogen. Slight chance of bursting which can spread disease | 2 | 2 | 2 | 0 | 0.01 |
| Anaemia | Decrease in red blood cells or haemoglobin in the blood can lead to hypoxia in the organs | 2 | 1 | 1 | 0 | 0.01 |
| Vomiting | The expulsion of infected material through projectile vomiting increases the risk of infection | 3 | 3 | 1 | 0 | 0.01 |
| Pneumonia | Serious fluid build and discharge from the lungs. People in cold climates especially vulnerable | 3 | 3(0.05 cold effectiveness) | 2 | 0 | 0.01 |
| Sneezing | Fluid discharge through sneezing greatly increases infection rates. | 5 | 5 | 1 | 0 | 0.01 |
| Sweating | The loss of fluid through sweating also increases infection rates due to poor hygiene. More dangerous in cold countries | 3 | 2(0.05 cold effectiveness) | 1 | 0 | 0.01 |
| Paranoia | Irrational delusions and mental symptoms. Victims distrust of others makes them unlikely to seek treatment or cooperate with others | 4 | 0 | 4 | 0 | 0.06 |
| Hyper Sensitivity | Increases likelihood of allergic reactions which can distract the immune system. Rich regions particularly vulnerable | 2 | 1(0.04 wealthy effectiveness) | 2 | 0 | 0.01 |
| Abscesses | Pockets of infected flesh are painful and act as breeding grounds for the pathogen, increasing infection rates when burst | 2 | 4 | 4 | 0 | 0.01 |
| Haemophilia | Immune system produces inhibitors that destroy factor VIII, preventing blood clotting. Infectivity increased | 3 | 4 | 3 | 0 | 0.01 |
| Pulmonary Oedema | Potentially fatal heart abnormality causes breakdown of respiratory system, releasing pathogen into the air | 7 | 5 | 4 | 2 | 0.01 |
| Fever | Increase in temperature, contagiousness and severe dehydration, which can be fatal | 9 | 4 | 3 | 3 | 0.01 |
| Inflammation | Inflammation obstructs bodily processes. Swelling can obstruct breathing and be fatal | 5 | 2 | 2 | 2 | 0.01 |
| Tumours | Pathogen disrupts cell growth pathways, causing uncontrolled, eventually fatal tumour growth | 11 | 2 | 0 | 4 | 0.01 |
| Diarrhoea | Pathogen active in digestive tract, causing infection through faeces and potentially lethal dehydration. Poor countries v. vulnerable. | 6 | 6(0.05 poor effectiveness) | 4 | 1 | 0.01 |
| Pulmonary Fibrosis | Scarring of the lungs causes shortness of breath and extreme coughing. Can be fatal when combined with intense exercise. | 6 | 3(0.05 humid effectiveness) | 3 | 2 | 0.01 |
| Immune Suppression | Pathogens attach to lymphocytes, suppressing immune system and allowing significantly greater freedom of mutation.Can be fatal. | 12 | 2 | 6 | 4 (+1 mutation) | 0.01 |
| Skin Lesions | Breakdown in the epidermis causes large open wounds which significantly increase infectivity | 8 | 11 | 4 | 0 | 0.01 |
| Seizures | Random blackouts and fits reduce the patient's ability to function independently. Can be fatal | 4 | 1 | 7 | 3 | 0.01 |
| Paralysis | Pathogen destroys motor neurons to cause paralysis. Significantly harder to cure and can be lethal | 10 | 1 | 5 | 1 | 0.1 |
| Systemic Infection | Pathogen affects multiple organ and tissue types, causing body-wide infections that spread fast and can be fatal | 17 | 6 | 7 | 6 | 0.01 |
| Internal Haemorrhaging | Arterial membranes break down, causing rapid internal bleeding and death | 12 | 0 | 9 | 7 | 0.01 |
| Dysentery | A complete breakdown in the digestive system causes infected sewage, dehydration, starvation and death | 19 | 8 | 15 | 8 | 0.01 |
| Insanity | Neuropathic action of the pathogen in the frontal cortex causes severe emotional and behavioural abnormalities. Significantly harder to cure | 18 | 6 | 15 | 0 | 0.2 |
| Necrosis | Large swathes of infected tissue lose blood supply and become fatal sources of gangrene. Decomposed bodies remain a vector of transmission | 27 | 10(10 corpse transmission) | 20 | 13 | 0.01 |
| Hemorrhagic Shock | Severe loss of blood volume causes oxygen deprivation, loss of consciousness and death | 23 | 0 | 15 | 15 | 0.01 |
| Coma | Neuropathic effects in the brain stem cause loss of consciousness and sometimes death. Significantly harder to cure | 21 | 0 | 15 | 2 | 0.24 |
| Total Organ Failure | Catastrophic cell death of multiple tissue types causes body-wide organ failure and rapid death | 28 | 0 | 20 | 25 | 0 |