Dr G S Javed,
Founder, King Consultants Education
There have been observations and reports that the patients affected by the COVID-19 virus are showing inflammation in the heart, acute damage of kidneys, problems in the liver and damage in the intestines.
It seems logical that other parts of the body get affected too. I started to apply the principles of #DesignThinking here.
There is one common element connecting all parts of the body – Blood. It is a connective tissue.The circulatory system is the only common connection to all the organ systems in the body.
Role of Blood in the body
Blood is a bodily fluid that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. Blood plays an important role in regulating the body’s systems and maintaining homeostasis. Homeostasis is the ability of a system or living organism to adjust its internal environment to maintain a stable equilibrium. 
Function of blood within the body 
- Supplying oxygen to tissues (bound to hemoglobin, which is carried in red cells)
- Supplying nutrients such as glucose, amino acids, and fatty acids either dissolved in the blood or bound to plasma proteins (e.g., blood lipids)
- Removing waste such as carbon dioxide, urea, and lactic acid
- Immunological functions, including circulation of white blood cells and detection of foreign material by antibodies
- Coagulation, which is one part of the body’s self-repair mechanism (blood clotting by the platelets after an open wound in order to stop bleeding)
- Messenger functions, including the transport of hormones and the signaling of tissue damage
- Regulating body pH
- Regulating core body temperature
- Hydraulic functions, including the regulation of the colloidal osmotic pressure of blood
The body closely monitors blood oxygen levels to keep them within a specific range, so that there is enough oxygen for the needs of every cell in the body. Blood oxygen level is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells, which collect oxygen from the lungs and deliver it to all parts of the body. A person’s blood oxygen level is an indicator of how well the body distributes oxygen from the lungs to the cells, and it can be important for people’s health .
Where does Oxygen come inside the body
The lungs!! The lungs bring in Oxygen. If the lung is affected for a long term, there is Oxygen deficiency to the organ systems. Organ systems might get affected and not perform their duty efficiently.
Now, which part of the lung deals with the oxygenation of the blood – Alveoli.
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called hemoglobin in the red blood cells then carries the oxygen around your body. At the same time, carbon dioxide that is dissolved in the blood comes out of the capillaries back into the air sacs, ready to be breathed out.
Blood with fresh oxygen is carried from your lungs to the left side of your heart, which pumps blood around your body through the arteries.
Blood without oxygen returns through the veins, to the right side of your heart. From there it is pumped to your lungs so that you can breathe out the carbon dioxide and breathe in more oxygen. 
But clinicians around the world are seeing evidence that suggests the virus also may be causing heart inflammation, acute kidney disease, neurological malfunction, blood clots, intestinal damage and liver problems. That development has complicated the treatment of the most severe cases of covid-19, the illness caused by the virus, and makes the course of recovery less certain, they said .
A systemic failure due to absence of oxygen is the core of the problem. This can be enabled if you affect the lungs. The lungs are the main source of oxygen for the normal functioning of the body. The blood is a medium of transport to all. An analogy would be absence of the lorry / train transport in the country. When this is reduced, it creates a demand-supply problem. For some sectors the demand is too high, and for some sectors there is abundant supply. For both you need money (oxygen). Lack of this money can suffocate the system (here, the human body).
In summary, it is a well-defined problem whose solution is the Covid-19 crisis.